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Pulled the engine and tranny today. It came out pretty easy with the front clip removed. But as has been SOP with this truck, I've found more to fix as well as some things that have me guessing LOL.
Engine removed

Looks like the firewall got butchered up some. I don't think it's unusual to have to do some cutting to get the automatic to fit but the small round hole, above and to the right of the main cutout is perplexing.
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The rear tranny cross member has some rust through that I can repair or replace depending upon how everything aligns with the SBC.
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I do believe those shocks are going to have to be relocated to the outside of the frame rails. Course if I put some more leafs back in the shocks will have to be replaced.
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The tranny's going to get pressure washed but I'm undecided on the TC. I believe it'll work on the 350 but don't know what kind of differences it may have from a SBC TC and if they'll be good or bad.
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On the top of the TH350 is a short tube with a 90 degree bend and a dimple for acceptance of a rubber hose. IS this a vent? -or- if not what is it's purpose?
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I'm seeing alot of needs on this truck but it's got a budget so full frame off isn't in the cards for it. At least not at this time.

Look what the 49 Chevy brought back for the 49 GMC.
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The numbers (3932388) say it's a 1969 350. It could be a 2 bolt 255HP or a 4 bolt 300HP engine as they both used the same casting number. The head numbers (3932441) say it could be a 69-71 350 with 1.94" intakes and 1.50 exhausts with a 76cc combustion chamber. Before they pulled it I went over and started it up, listened to it, saw 50psi oil pressure, temps staying around 185, no pings, no knocks, no smoke and no leaks.
It's been a daily driver for a couple years. The owner I bought the engine from doesn't know anymore than that. He bought the truck (72 C10) because the engine ran so good.
Apparantly not as good as the stroked 383 he's having put back in and bolting it to the TH350 thats still in it. Like me he may explore a 700R4 at a later date.
I'm going to guess it's been rebuilt at one time as it ran and sounded too good to be original. Mileage is unknown, his odometer showed 33K so it's either turned over or ran for a time with it disconnected, who knows....
He kept the VC's, starter, dist, alternator & bracket, Edlebrock 4bbl and fan to go on his new engine. So I'll be replacing those. Otherwise I'm just going to clean it up, give a good coat of orange paint, slap the TH350 I already have on it and fit it in the Jimmy.
I'm hoping I may be able to reuse the Jimmy's welded-on motor mount perches with a new set of clamshell motor mounts. I'll be knowing soon.

The tube at the bellhousing area is a vent. Just be sure it's clear. Has the original crossmember been removed in the bellhousing area of the frame? If so, there's going to be an issue with frame flex at the rear of the front springs. It's usually a good idea to replace that piece with a dropped-down piece of square tubing that has clearance for the transmission and still stabilizes the spring mounts.

If the stamped engine number ahead of the passenger's side cylinder head has a "T" in the suffix letters at the end of the number/letter sequence, the block probably has 4-bolt main bearings.
Jerry

I think the small round hole on the firewall was for the original stomp starter.

If anyone should wonder about the usefulness of a tractor w/an FEL wonder no more. It definitely makes lifting and moving an engine and other associated heavy objects around very easy.
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Using the Kubota BX23 I carried the 350 down to my cleaning station beside the shop and gave the sealed up 350 a well needed degreaseing and bath.
It cleaned up pretty good and I found the engine VIN code numbers at the right front.
According to the numbers it was made on Nov 11 1969 at the Tonawanda plant, is the 300hp version that came with a 4bbl and hydramatic tranny and came in either a Biscayne, Bel Air, Impala or Caprice. No definitive answer on whether it's a 2 or 4 bolt main. Since it's going to be a cruiser for as long as I keep it I'm not overly concerned as 300hp is more than enough for that. Perhaps I stick a scope up the oil drain hole later LOL....

Whilst I was picking up the HEI dist they forgot to include with the engine I measured the distance of the clamshell motor mounts in the C10 that the 350 came out of and compared them with the same clamshell mounts that are in the GMC and they measured out exactly the same width, 16 1/2" center hole to center hole and 22" top to top. Test fitting will determine if they're where I need them or not lengthwise. The mount perches are welded in and I'm not inclined to cut and move them so if they aren't right I'll either make up some plates or try one of those adjustable engine brackets that'll mount to a clamshell style mount. It'll all depend upon how close it is.

The flexplates on the 250 and 350 measured out the same so I decided to try the 250's starter and it bolted right up. Although they have different part #'s, both the 250 & 350 starters use the same Bendix and solenoid. I'm guessing the difference is in output torque. I'm going to try to use the 250 starter and if it works thats $100 saved...
After a good degreasing I gave the 350 a couple good coats of Chevy Orange. Going to stay old school with it.
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Don't pay any attention to the blue VC's, I picked them up for $10 from a local Mom & Pop FLAPS to cover the topend. I've ordered some chrome goodies to replace the parts it ain't got. Chrome = HP right?
I also picked up a pr of 265 exhaust manifolds on ebay. They look to be in good usable condition. The left side has the generator bracket cast it, I'll be leaving it as is as long as it doesn't interfere with anything. Hope they don't sufficate the 350.
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And ordered up the needed gaskets from Rock Auto.

That cross member was definitely cut out Jerry. Once I get the 350 & tranny in and situated I'll look into a brace to shore the frame up behind the spring mounts.
I'd say you are correct goneagain, the hole is too round for a butcher job LOL.
Dave

Rub it in, Dave. Rub it in.

JW51, you got that tractor yet LOL....
Brief update.
UPS arrived early today. Got back from my new favorite store (a hot rod specialties building stuffed plumb through with all kinds of goodies) and was greeted with the set of Corvette 265 exhaust manifolds.
They are in very good shape and are ready to bolt on. I am surprised at the port size difference. The 265 ports are visably smaller than the 350's.
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I also received the new exhaust gaskets so I matched them up to both the heads and manifolds. The gaskets are marked for the 265 but they are the exact same size as the 350's exhaust ports. They are wide enough to work on the 265 manifolds so no problem there. The port size difference can be seen better in these pics.
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I decided to measure the differences.
My rough measurements of the ports are:
265, exhaust ports = 1.19" X 1.19". Exhaust pipe port = 1.75" (basically will use 1 3/4" exhaust pipes.)
350, exhaust ports = 1.36" X 1.36". Exhaust pipe port = 2.16" (basically will use 2" exhaust pipes)

I'm planning on having 2" exhaust pipes/mufflers as I have most of the parts collected up but these manifolds
dump to 1 3/4 and use a flat gasket instead of a doughnut. I'll have to do some research to see how that'll work out.

Dave

Got the engine mocked up in the frame. I haven't determined which motor mounts to use yet so I guesstimated how the engine would sit with the OEM clam shell brackets by using a couple pieces of wood. I'm hopeing my wood guesstimate is wrong as the engine is sitting to low. I removed the #5 plug to gain some clearance. Ain't no way to reinstall it as is....
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Heres a shot of #7 plug peaking around the backside of the steering box.
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All the pics I pull up on the SBC's in Stovebolts show them sitting higher. So I'm researching motor mount options.

Moving on, it was good to see that the motor mount frame perches and rear tranny mount don't need to be moved and will work where they are. With the tranny resting on the mount where it will bolt up (need new rubber mount) the triangle bolt boss for the motor mount bracket is centered directly over the frame mounted clam shell rubber mounts. In this position there is just enough room for me to fit my fingers between the HEI dist and the firewall.
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Theres plenty of clearance between the long shaft water pump and the radiator and if I get the engine up a little higher I believe it'll run a clutch fan.
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Inorder to get clearance for the fuel pump the right side shock had to go. The top shock mount was a bolt welded to the upper frame lip. It'll either get moved to the outside of the frame rail -or- totally replaced by a 50's era tube shock setup.
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Based on the gap between the bellhousing and firewall thats already cut, the whole assembly can be lifted a couple more inches.
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It was level.
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Since the powerplant sits in basically the same position the driveshaft should work as is. When I pulled it I thought the U joints felt rough so I'm going to replace them both. Wouldn't you know it that they'd be odd ball too.... Unless Chevy used U joints with differing axis and cap size measurements, they look like a Ford 1310. I thought my quick once over of the rearend indicated it was an 8.5 10 bolt. I'm not so sure now. Will know more on that later.
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Dave

The engine & tranny are shoehorned in and permanently bolted in place using the OEM motor mounts and brackets that fit a 69-72 C10, front and back. Actually there are more years and models such as Chevelle's, Impala's, Caprice's etc., but I concentrated my research on that model and years and can verify it. To gain alittle more clearance on the left side I offset the engine by approx 3/4" - 1".
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To do this I added spacers on the left side and redrilled the long mounting bolt hole in the right side bracket. I could have gone more but I really didn't want to even go this much so I compromised....
Even with the offset none of my left side exhaust solutions fit, so I unbolted the steering gear box and started mock fitting.

Good news is the 55/56 Corvette manifold fit with approx 1" gearbox offset and clearance for the dipstick.
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Bad news is it dumps directly over the OEM motor mount.
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I believe some creative pipe making could make it work but it'll have to be very creative.

I tried a borrowed set of block hugger headers.
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Inorder to even get the left side in I had to notch the hole in the firewall more just to get enough gearbox offset and it is WAY too far out for my tastes. I don't know if I could put enough bend in the pitman arm to bring it back in....
The right side looked good tho.
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I decided to start researching power steering. THAT is the way to go if one has the budget. Partial to full kits are available so I've decided to start piece mealing one together. In the mean time onward with what I've got.

Decided to revisit using the 96 5.7 left side manifold. The ports are the proper size, it came on the performance cars of the day and it dumps back between cyl's 5 & 7 which is close enough to bolt to one of the existing exhaust pipes.... The main problem with using it was the dipstick. On the 69 350 there is only one provision for an oil dipstick and it is left/drivers side block between cyls 5 & 7, yep, conflict. There is a small gap between the head and manifold which I decided to exploit. Head bolts block going through either side around the dump/collector pipe so I decided the steep cost of a flexible dipstick wasn't in the cards. So with a little grinding on the backside of the manifold and a slight squeeze at two spots on the dipstick, I got it bolted up and I could read the dipstick.
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Ofcourse there was/is one more drawback, isn't there always? And that is access to plug #5.
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There's 2 work arounds tho, use a shorty Accel plug or use a wrench, both doable.

Theres a couple more exhaust options that I could try and I've got one more I can try that won't cost me unless I use it and that is a sorta inverted Rams horn. Instead of the runners being above the plugs this one routes the runners below. It was OEM for some 70's 350's in Camaro's and Caprices which usd the same motor mounts as I've put in the Jimmy so I'm going to try one. The area between the steering box and head widens as you go lower so it should fit and clear the mounts. I also like that there should be no plug access problems too. Should know in about a week.

Got a piece of 2" angle iron so I'll be making up a bracket to kick the gearbox out. A friend says he can heat the pitman arm up enough to bend it so hopefully I'll be able to move on soon.

I also id'ed that U Joint, they called it a bastard joint LOL. It came on certain GM models namely Buicks they said....
Danged thing cost $23, I'd say they named it correctly.....

So I had to have a SBC powered Jimmy LOL....

Hi, On my 1953 GMC with a 350 I moved the shock mounts to behind the axle mounted a 69 c10 power steering box outside the frame in front ( the reason for moving the shocks) with the CPP kit. Double d joints and rod mounted to original steering column. Also a set of rams horn exhaust. If you need pictures pm me your email. Steve

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Good pics Steve.
Had a distinguished Stovebolt visitor stop by bearing gifts.
HRL
He just happened to be passing through to the get together up at Stovebolt HQ (I hope to make it next year) and he must have decided the 235 on the trailer and the 216 in his Dakota's bed wasn't enough ballast for his Goldwing so we loaded up the 250 on one of his home made transport stands and off he headed north. On his way to my place he stopped by another Stovebolters place in middle TN and picked up some springs for me. That and a servicable Holley 600 cfm carb constituted a trade we were both very happy with.
This Stovebolt community walks the talk folks, theres alot of good folks here. I was glad to meet up with him and hope to meet more.
The springs are used but in good shape but more importantly they're complete.
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Made up a bracket to offset the gearbox using 2ea 2" angle iron pieces welded together to form a 2" channel iron section.
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And after soaking the pitman arm for 2 days with regular blasts of PB Blaster I finally got it off. I used an impact, the wrench just tightened it up to hold it in place.
I know I'll be bending it (or having it bent) but I'll hold off until I get the front suspension situated. Those replacement springs are going to raise the truck back up and I want to check geometry and fitment before bending.

Thinking out loud now. I counted the splines on the 49's pitman arm and I came up with 28 not counting the 4 large indexes. If the indexes are counted as splines that would equal 32, which is what the Vega's pitman arm count is and perhaps others. I'll be doing more research on that.

Got a few more things done, I'm lining up a couple helpers to put the front clip back on in the next week or so.

I had a local machine shop heat and bend the pitman arm for me. I spec'd a 1-3/4" bend back but they said 1-5/16" (approx) was what they ended up with.
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Thats OK, the pitman arm kicks out a little but it's close enough for now. Power steering is definitely in this trucks future.
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I really liked how the left side 75 Camaro exhaust manifold fit. The runners route below the plugs and clear the OEM motor mounts just like they were designed to, matter of fact they were LOL. So I paid for it and ordered the right side. All plugs and oil dipstick were easy peasy except plug #5, still need to use a wrench but access is good. Just not enough room to get a socket on it. Those manifold's ports are the same size as the head ports so no loss of flow, plus they were spec'd fro the performance engines of the day.
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I pulled those bowed monleafs, went through those used springs I got, used the best parts and decided to try removing the 3 smallest leafs and go with 5 leafs. It sits alittle higher and the reverse bow is gone and they pretty much sit straight, parallel to the frame and ground. With the shocks mounted it didn't bottom out on the stops with all my 200+lb's bouncing so I'm going to keep it like that for now. Should I decide to add the other 3 leafs back I can then go with 50-54 OEM shocks and mounts. Until then I'm running what I got.
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Also installed new U joints, the front is spec'd for a 79 Nova, the rear for a 57 Old's 88 (bastard joint).
Pulled the rear drums and discovered the springs were badly rusted and the right side self adjuster just laying in the drum. Bought a kit for a 79 Nova 9-1/2" shoes/drum and it seems to match up.
Dressed the engine up alittle and it's got the old school look I'm shooting for.
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Getting closer.

Been spending alot of time under the GMC lately. I'm threatening to retire from under vehicle work after this project, a man has got to be thinner & spryer than I am currently and I don't see me getting that way anytime soon LOL.
Got the driveshaft reinstalled, it bolted right up with no mods needed. While under there I had to cut away some of the dual exhaust to gain clearance (for me). I did it in a way that would enable reuse incase I wanted to go that way and surprise, I did. Surprisingly both down pipes that bolted to the 250's manifold were close enough in depth and angle to be reused on the 350's Camaro manifolds. I had to replace the 2 hole clamp to 3 hole to match the manifolds otherwise they bolted right up. They hang down alittle too far for a clean look but not so far as to be lower than the straight axle. I was able to use a splice and dual clamp on the passenger side but had to try my hand at flux core welding the down pipe back to the rest of the exhaust pipe on the left side. Somehow I got it welded but it looks so bad I'm not showing a pic.
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Also while under I dropped the trans pan and replaced the jammed kickdown cable. A new cable to fit a 69 Impala fit perfectly. Yes. I' keeping good records of this Frankenstein truck LOL.
Since I was already down there a good visual inspection was inorder. This truck must have lived alot of it's life up north due to the rust and rust repair it has. The frame and crossmembers have been repaired in several places. The welds/repairs look good but if I keep this truck it is going to get either a newer S10 frame or I'm going to take a harder look at my brothers 94 Dakota he's got sitting with a bad engine. That said, the truck is still solid and can go as is for now.
I got most of the wiring done, the fuel lines run, the vacuum lines run, the throttle & kickdown cables installed & adjusted so I said what the heck, lets try to start it. Well, the 250's starter will not work. The main difference being it doesn't throw the bendix out far enough to engage the flexplate. It's in the nose casting so no workie. It was good as a core for a proper 350 starter tho...
So, after enough cranks to get fuel from the tank to the float bowls the 350 sprang to life! I only ran it long enough to verify oil pressure and charging which both were spot on so I shut it down. No need to burn it up. Those Smithy glass packs are definitely too loud altho my SIL thought it sounded great. It's definitley going to visit a local muffler shop to clean up my, ummm, hillbilly rigging and replace those glasspacks with a set of 2" DynoMax Super Turbo's to mellow it out alittle more. I bought them for the Chevy 235 conversion but can get another set when that happens.
Also did alittle cleanup in the interior. It cleaned up pretty good considering. Since the budget is screaming "mo mas" I made the tactical decision to try a cheap set of faux leather (vinyl) black seat covers on those ripped up seats and surprisingly it'll do until I decide the long range plans for this project. I just need to research how to get that off-white console black to match. I think they make a paint that'll work, we'll see.
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A couple of retro strike plates and latch clips now allow the doors to close properly and stay closed. Don't need doors flying open on a cruise... Course I'll have to decide if I want to stay with a wing vent doors (like the passenger side) or solid pane doors (like the drivers side). Kinda wish the vent window was on the drivers side tho LOL....
I also ordered a new windshield rubber seal to replace that painted over abortion and a new seal for the gas filler to cab. Also picked up a new trans oil cooler to mount behind the grill once the clip is reinstalled. I did some horse trading back when I got the Chevy and picked up alot of good usable stock parts for these 47-54 AD trucks, a better fuel filler tube and a radio block off plate will fit the GMC perfectly. A glove box and heater are on the "to be ordered" list....
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I've set up a couple strong backs to help put the front clip back on this weekend. Then I can determine whether I can go with a mechanical fan (preferred) or electrical.

For the price of 3 racks of my slow smoked E TN dry rubbed babyback ribs, my crew of 3 strong backs made short work of getting the front clip mounted and made shorter work of relieving me of said ribs. But it was well worth it.
Had to cut alittle of the inner fender away for the repositioned gearbox. Course getting the clip mounted opened up a whole new can of worms to deal with.The engine sit's too low for a mechanical fan so it's going to get a 16" electric, probably make up a shroud to mount it on. Got 3-3/4" of clearance to play with. Another mod deals with the lower radiator gooseneck, currently it makes 90 degree bend upwards at an angle not conducive for unrestricted coolant flow to the water pump, I'm thinking of cutting the bend off, will be studying on that.
I think the trans cooler will be alittle safer tucked up behind the grill instead of ty-rapped to the straight axle like it was before LOL.
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One good thing to come about with raining everyday is all the shop time I'm getting. I really need to put some corn out tho.....
Due to the radiators lower gooseneck having a 90 degree bend and pointing straight up I was unable to use the flex hose without a severe collapsing bend in one of the bends so I made up a template of the needed hose with a coat hanger and headed to the closest FLAPS and went through all their hoses. Not finding anything that would work I got the closest match, a lower hose to fit a Jeep Cherokee w/a 4.7 and tried it. It had the required ends, 1-3/4" and 1-1/2" but still crinked at the bend. So I cut it in half, ran to a plumbing supply and got a 1-1/2" 90 copper elbow and 6" of 2-1/2" copper pipe. Using 2 inches at each end I layed the solder to it and spliced in the 2 rubber pieces and had me a workable lower radiator hose.
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I used a 18" flex hose for the upper and will probably replace it with a smoothie one of these days. Also made up a 6' loop of heater hose and hooked it up. Presently there's no heater to connect to but the hoses are there.
In studying up for the 16" 2700 CFM (as advertised) electric fan, I was about to purchase a shroud for it(man they're proud of them) then decided to use some sheet metal from my stash to make one up. The GMC radiator sits back a minimum of 1/2" at the top and 1-1/2 at the bottom from it's frame so I cut up the sheet metal, mounted the fan to the shroud then bolted it to the radiator frame.
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So with everything hooked up I started filling the radiator and wouldn't you know it, the waterpump started leaking from the weep hole. So off to the FLAPS for a new waterpump back to install it.
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I put the fan sender in the manifold water jacket port and wouldn't you know it, it leaked too... Since it has to provide a ground to turn the fan on which means no teflon tape or pipe dope so I backed it out then ran it back down and that stopped the leak.
So, with everything put back together, no coolant leaks, no trans fluid leaks and no oil leaks I fired that puppy up.
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Good news is I avg'ed 45 psi oil pressure above idle rpm, never got over 190 degrees when idled & ran for over 1/2 hr
and it charged and showed a steady drop in charging volts once the battery got recharged. The tranny engaged in all gears and spun the rear wheels. Power brakes stopped 'em from spinning.
The tapping sound is actually an exhaust leak at my poor weld joint, the engine is pretty quiet otherwise.
Played around a little with the idle settings and timing using the vacuum gauge. Both idle screws were out maybe 1 full turn and the electric choke worked, Using the vacuum method I'm at 12 degrees advanced at idle. I'm going to try the max advance setting (35 degrees with no vacuum) @ 3k rpm and see if it changes. Book calls for 4 degrees BTDC which isn't enough IMHO...
Put the grill back on and buttoned the clip up.
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If theres no spots under it tomorrow it's coming off the jack stands and advance on to the next stage, road test.
Dave

Finally took a shakedown cruise. I only wanted to go a mile or 2 on back roads to get a good feel for whats working and whats not and to see what it is I traded for. The drivetrain was working so well I expanded a few more miles and made a stop at a carwash. With a yr or so of garage grime washed off I headed to a stretch of 2 lane thats really straight so I could open it up a little. For about 3 miles or so the 350 w/the TH350 purred. Oil pressure was at about 35 and temp around 180. Thoughts of interstate running started popping in my head but unfortunately it started acting like it was running out of gas and finally died. My aftermarket gas gauge said there was alittle over 1/4 tank and I could hear gas sloushing around in the tank when I shook the truck but when I pulled the line off of the carb it was dry and there was no squirt of fuel when I tested the accel pump. So I made the fateful call and had some gas delivered. The 5 gals put it over 1/2 tank and it started and I headed home. About half way home it stuttered and died again. I let it set a couple minutes, started it back up and it made it home. But another problem cropped up on this home stretch run, the front brakes.... When I went to brake at a stop sign it practically threw the truck into the left lane. It was violent! And when I took off I could tell that one or both of the front brakes were dragging/grabbing. I slowed and could see smoke from the right front and I could smell the tell tale smell of hot brake pads. VERY HOT brake pads.
I nursed it home and when I was trying to back it into it's stall the right front brake just locked up and still won't turn. Had to use a jack to manuver it back.
So, I'm looking at replacing the fuel pump, fuel filter (under the tank), both front calipers, both soft lines, turn the rotors, adjust the tie rod alittle to fine tune the alignment, setup an appointment to get to exhaust how I want it to sound (those Smithy's are too loud) and plug all those firewall and toe board holes....
It rides rougher than the stock 49 Chevy but it did clear the railroad tracks and handled the road fairly well. I can see adding the stock 50's tube shock setup and power steering. Those danged 14" tires mounted on those old school Cragers are hardly worn so I'm going to leave it's profile as is, that low rider stance is kinda growing on me, I'm thinking about keeping it.
Fini
Dave

Fini part deaux. Shakedown cruise #2 went a whole lot better. All the previous brake and stalling problems were corrected. After approx 100 miles and a couple stops the truck ran so good I washed and waxed it, inside and out, centered the steering wheel and hooked the Oooga horn up, wired the tach and power port up and installed the overflow tube. It rides like a buckboard so I'm going to have to explore for a new cruise route for it. Otherwise color me happy LOL.
Back road crusing

FINI
Dave

Update: I know I've said fini twice but what the hey.
I posted earlier about a persistent rough idle caused by a vacuum leak at cyl's 6 & 8. I finally parked it long enough today to address it by swapping out the Weiand intake with it's gobs of RTV ozzing out of every joint surface with a brand new Edelbrock Performer EPS dual plane intake without gobs of RTV....
I'm happy to report it now has a lot smoother idle and it's pulling a nice steady 19" of vacuum at idle.
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I also pulled the plugs for a look see. They have approx 700 -800 miles them. They're Champion R45's.
This is #1 plug, the others look similar.
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It looks like they're too hot and/or a little on the lean side. When I readjusted the mixture I turned them out just a hair to get the steady 19" reading. So I'm going to check them again in 500 miles or so to see if they look better.
Thinking about picking up a set of R44's if they don't.
Dave

Unless you were idling for those 700-800 miles, your idle mixture screw setting would not be responsible for those plugs looking like that.
Your lean condition would more likely be coming from a need for a change in jets/metering rods.
Dr. Lincoln will be in soon to assist you, or maybe Dr. Jon (not the Right Place, Wrong Time Dr. John, but the carbking guy).

Well, theres one thing for certain, that 350 is exercising it's dual lungs a whole lot more than peacefully idling LOL. Edelbrock makes a carb tuneup kit with all the needed goodies plus destructions, I'll probably be looking at one plus some R44's. Meantime I'm going to see if a properly sealed intake improves it.

Re. our esteemed Dr's of ICEs. Unfortunately their collective opinion of the AFB clone is such that I'm afraid their recommended course of action would include a deep pond, a nice cool shady spot and a fishing pole in need of a sinker LOL.

I respect their opinions, but everybody and their brother puts them on their hotrods around here. I have one on my '49 and it runs great and the plugs look normal after 1,000 miles. If I ever have trouble with mine, I will contact carbking and see if he has an AFB designed for a 350.
We have 100 pound catfish which live in swift current, so an E-clone with its square shape, should hold the huge baitfish on the bottom.
I did not realize that your plug issue occurred before you were able to fix your leaky intake seal. I hope that was your problem. Your new spark plugs will tell you after a while.
Carl

You know what they say about opinions, man I best stop before I dig too deep. I too respect their opinions and enjoy their tall tales LOL.....

Those clones are real popular around here too. Matter of fact of all the problems and hillbilly rigging I've been dealing with on the Jimmy, the E clone carb hasn't been one of them. Once I properly adjusted the electric choke (I likee) it starts so fast that I've got to make sure I unplug the dist power line if all I want to do is just rotate the engine.

As an aside, the FelPro gaskets I went with didn't have the holes opened up for manifold heat. After much thought I decided to open them up so as to get that heat under the carb. This old cast iron 350 is cold natured as it is. I've noticed they make a spacer should the heat be too much so I'm monitoring that among other vitals.

re. oil pressure. I went with 5w30 oil and based on the amount of time it takes the lifters to pump up and quiet down I'm thinking of going w/10w30 on the next oil change. Oil pressure is good but that second or 2 of clacking would be a callback to me back in the day.

Have you adjusted the lifters properly? It sounds like they're running at or near the top of their travel if they have to pump up every time the engine is started. The companion cylinder adjustment I recommend works on hydraulics as well as solids- - - - -get a cylinder at its split overlap point and adjust both valves of the companion cylinder to zero lash plus 3/4 turn of the rocker arm nut. I've adjusted thousands of hydraulics that way without a problem, even on radical racing cams.
Jerry

If you're running an aluminum intake, is it really a good idea to be running exhaust gas through it? Does it actually have a heat riser passage? Unless you've got a heat riser valve on one side, the exhaust gas isn't going to flow under the carb anyway.
Jerry

Haven't adjusted the valves yet. I've got your method archived....

re. manifold heat. The old Weiand manifold had exh heat under the carb and the old gaskets looked like the heat "burnt" the holes open. The new Edelbrock also has the cast in heat passage under the carb.
Instead of allowing it to just burn through I cut the 2 openings square to match the exh ports in the heads.

When I was researching the manifold swap I noticed some gaskets would come with metal block off plates to insert in the heads exh passages and the gasket was placed over them. Prevailing thought is manifold heat was good for street engines and not for race engines.

The manifold heating design is similar to the old ACVW's design it that the heat passage is tied to both head banks which provides a high/low pressure differential to flow the heated exh from one side through the passage to the other. Theres no valving just a pressure differential. I would notice one side (3/4) was so hot it couldn't be touched while the other side (1/2) wasn't as hot and could be touched. It worked on the ACVW's so perhaps the same or similar principle works on SBC's.
Will it be a problem flowing heat through an aluminum intake? I dunno. It was definitely designed for it.

OK- - - -the website just ate a long reply! If the heat passage in the manifold is open, there needs to be a functioning heat riser valve installed in the passenger side exhaust pipe. The only time exhaust heat under the carb is needed is during warmup, and without a heat riser with a functioning bimetal spring, there won't be enough exhaust gas moving under the carb to do any good. Once the spring heats up, flow under the carb goes away, as it should.

The firing order and the extremely restrictive exhaust on air cooled VW's kept the exhaust flowing, and that carb was so high above the engine heat it needed a hot intake all the time, especially in winter. Small block Chevvies are not VW's!
Jerry

Must be karma LOL.....
I've lost some of my best stuff by an inadvertent fat finger, not to say that happened to you LOL....

Actually I'm fine if there's minimal to no heat flow though the intakes exhaust crossover passage under the carb.

Back in the 70's I did some line automotive parts swapping work for a living, mainly brakes & tuneups and don't ever recall running across or having to replace an exhaust diverter valve on a V8 Chevy. Course vehicles of that era had a nightmare of plumbing, vacuum controls, air pumps and other abortions of engineering in trying to make carburated engines compliant and I learned early on not to fix something that wasn't broke. That and the mixture of SAE & Metric drove me into the communications trade......

Anyways on an unrelated note. I got so tied up with this GMC that I wasn't able to take as much advantage of one of the best growing seasons we've had around these parts in years. We've actually experienced one of the wettest July's on record. That said and even tho it's late, I just may have some Indian corn for autumn display. It sure took it's time breaking through....

Yep, that stuff has a mind of its own. My friend down in Florida has a couple of farms in NE Georgia under contract to grow it for his heirloom grits/cornmeal grinding operation. Good stuff!
Jerry

Performance update:
While on my regular cruise today I took note of the criticals and thought I'd pass them along for general info.

I was partially concerned about running an electric fan over the engine driven fan with the thought that it would put an unnecessary drain on the electrics even though I'm running a 60 amp alternator. It seems my doubts were not realized and have come to the conclusion that an electric fan is the better solution.

A brief over view.
The engine is a 69 300HP 350 driving a TH350 trans and an 80's era Nova rearend (ratio as yet unknown)
Electrics are 12v with a 60 amp 3 wire alternator and an HEI ign.
The fan is a 2700 cfm 16" model mounted on a home made shroud and controlled by a 200 on / 185 off sender.
Radiator is a stock 49 GMC with 50/50 anti freeze, a 160 degree thermostat, a 4lb pressure cap and an overflow tank..

**note** The GMC overflow is different than the Chevy as it's tapped into the highest spot on the radiator and not in the gooseneck housing the cap. I'm going to guess once the pressure rises the coolant level enough to reach the high spot it'll just flow unimpeded out the overflow tube. Since I route this overflow to the overflow tank it pulls it back into the radiator upon cool down and I haven't had to add any coolant yet.
There is no provision for the cap to open and dump the coolant out an overflow pipe. If the cap does open theres no place for the coolant to go except perhaps out the gooseneck which it has never done yet.

No heater at this time.
No front bumper apron at this time.
Trans cooling is via a separate trans cooler mounted below and in front of the radiator.

Today the outside temp was a very comfortable 72 and I avg'ed 50 mph on the 1.5 hr cruise. This includes 1 short red light idling, some 65 mph stretching but mostly 40-50 mph cruising.
Other than the amount of time it idled while I loaded up the garbage for the dump run, approx 4-5 minutes, the fan never came on again. The engine temps never got above 195 and avg'ed 180-185 the entire trip. Oil pressure avg'ed 35 psi. So total cooling was via unforced air moving through the radiator.

I have noted on 80-90 degree days the fan does come on more frequently as the engine temp will avg 190-195. Short idling will turn it on as will running 60mph or higher but once the speed is an avg of 55 and under the temps will drop enough to turn the fan off and keep it off until it hits the above instances again. I haven't run it over 10 miles on the interstate as of yet but he highest temp I've seen was around 205-210 and seemed to stabilize at that point.
I'm about ready to stretch it out much further on the interstate and will report any problems then.

So in conclusion it seems the stock radiator will handle a somewhat stock SBC without AC or P/S and maintain proper operating temps with a coolant temperature controlled electric fan and shroud with minimal drain on the electrics.

And how hot does the trans cooler get with no fan forced air? Cool enough to touch but don't hold your hand on it long LOL.
YUMV
Dave

The GMC has been getting alot of road time and has been the case, yet another existing problem had to be addressed, the cruddy fuel tank. After the 3rd stallout since resurrection I decided swapping the fuel filter and blowing the line back towards the tank on the road side was enough. I had the Chevy's tank boiled and cleaned out by a local radiator shop and although it was clean and shiny where I could see inside it, it never stopped producing rust flakes in the filter so I swapped it out with a like-new tank I got on a trade and haven't had any fuel related problems since. So I ordered a brand new tank from a popular classic truck aftermarket provider and got it swapped out today.
I got a good feeling when I first saw the box's labeling. It clearly said what was supposed to be in it.
Pic
Mfg by Counterpart, quality assured:
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The tag says it was pressure tested on 8/23. I'm going to guess of last yr:
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It looked as good on the inside as it does on the outside:
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The original SAE threaded extension screwed in and the new aftermarket SAE shut off valve screwed on to it and neither leaked on my bench test:
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I liked the unfinished look so well I shot it with some clear and installed it au-natural:
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I cut up some old inner tube for new bottom mounting cushions and mounted it. The straps lined up as did the filler tube and short hoses. The notches on the backside lined up with the cab braces just like the OEM did. I didn't have to modify a thing. So I thought that in itself was worth posting about LOL.
With the addition of the glovebox and high beam indicator I believe this thing is ready to extend it's range out.
Dave

Ran into a real strange problem while out cruising on the GMC's 1st night cruise last Sat night. All the lights worked when static tested so I didn't think anything about trying it out at night.

When dusk hit I turned the lights on and carried on. After a short while I started noticing the ammeter jumping around from charging to "0" then I notice the gas gauge, an aftermarket Autometer gauge, started showing erratically, from 1/2 full to 1/4 full and back again. The gas gauge has been very steady before this time The voltmeter was showing 14 1/2 volt charging which is a volt higher than normal and while all this was going on the electric fan stayed on, even when temps were under it's shutoff (approx 185 degrees). It got me home and I didn't work on it until yesterday. /

Heres what I found, a wiring issue with the old cloth covered right side head light wiring, a loose toggle switch which is my bad, a blown Hi beam indicator lamp (maybe the original 6 volt, I couldn't tell) and a massive current draw that would come and go due to vibration and bouncing around.
The right side headlight worked on Hi beam but not on low beam. The low beam 20amp glass fuse was blown which killed lo beam on both headlights. The Hi beam indicator was blown. So I made it home running Hi beams and didn't know it.

The truck is a mixture of old and new wiring. The headlight wiring is old cloth covered and was wrapped in elec tape by persons unknown for how long unknown.... What happened is the low beam wires insulation frayed as did the ground wires and the vibration caused them to short together which blew the fuse. Had to cut away alot of tape to find it. The elec fan circuit I ran with new wiring uses a ground to throw the fan relay. I re-purposed a toggle switch and it's 2 wires someone had installed on the dash for purposes still unknown to me and I used it as a fail/safe toggle switch to throw the fan relay in the event of a sender failure.
The switch wasn't as tight as it should have been and the bottom terminal started making contact to the metal dash due to the looseness and vibration. I corrected this most-scosh.....
Replacing that blown HI beam indicator lamp was probably the most trouble. Due to the firewall mounted power master cylinder and the bracket under the dash, there was barely enough room to reach the backside of the gauge while pushing the lamp socket back in.

So it looks like 3 separate electrical problems hit at about the same time.
I'm really glad I kept the ammeter wired in the truck. Although the voltmeter is a better indicator of the charging systems performance, the ammeter is a good indicator of the entire trucks electrical performance.

Went on a nice 2 hr cruise today and all is well, for now anyways LOL.

Jimmy's got new skins, in the front.
Finally swapped out those tiny front tires with some with a little more meat to them.
The originals were Cooper Cobra GT 215 60R 14's. It sat the front end so low I couldn't slide my low profile jack under the front axle and I equated it's cushioning to that of a buckboard wagon in a John Wayne movie.
I was actually forced into the swap as the right front tire's steel belt must have separated causing a large hump (visible in one of the pics), this made the buckboard ride like it had square wheels.

The new tires are the same size as the rears, Cooper Cobra GT 225 70R 14's and they have nearly 2" more side wall which I hope offers some cushioning. They added nearly 2" of front end lift but the truck still maintains a lower front profile, but not as much. I can definitely live with it. Rain and other chores is delaying the test drive so hopefully it'll ride much better.
A couple pics of the tires side by side and mounted for comparison.
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Pic
Pic

Hate to keep beating a dead horse, OK not really, but I finally got to try those new tires out and man, what a difference those additional 2.7" make.....
The ride is much much better because theres more flex in the additional sidewalls. The steering is now as good as the skinny tire'd Chevy 3100 since I can run the full 32 psi in the tires without effecting the tires flex.
Even tho these small 14" wheels with lots of sidewall goes against the prevailing profile of tall wheels and skinny tires, I'll take ride quality for 100 Alex.... LOL
I think the profile still works. Old school baby...
Pic

Dave

Looks good to me.👍🏻

I do Like it. Good Choice!

Thanks. I'm really liking those taller tires upfront.

With the ambient temps around 65 today I took the GMC out for a nice back road cruise. I'd say the avg speed was 45 with some slower and some higher speeds and a couple stop sign stops.The entire route is approx 60 stress relieving miles. The cooling fan did not come on once during this cruise.
The temps avg'ed 170-180, never getting above 185. Since I don't have a heater yet I'd say this isn't high enough to provide adequate heat in the upcoming colder days so I may up the thermostat to a 180. On the front burner is deciding how to heat the GMC. I may move the Chevy's Arvin recirc over to the Jimmy while I do it's engine swap. I dunno, still ciphering this one out as the Arvins blower motor is still 6V. Course the Chevy will become 12v on the engine swap so I'm going to have to deal with it anyways LOL. It's always something.....
Man, it was a VERY relaxing cruise, that 350 SBC has a nice low rumble at 1500 rpm.....
Dave

Well, the ole Jimmy broke down on me and I was about 40 miles out on my normal cruise route we it started acting up. Problem was whenever I let up on the gas to make a turn or slow down due to a curve it would act like it was going to stall out. After about 5 times doing this it died on the 6th..... And wouldn't restart.
Good thing I was up hill from gas station so I coasted in and began troubleshooting.
Pulled the air cleaner and the 1st thing I noticed (and heard) was gas perculating out of the secondaries and dripping down the side of the carb. 1st though was the engine had got too hot but the gauge indicated temps no higher than 175.
So I climb back in and slowly go to WOT then spin the engine. It starts begrudgingly but won't idle. Runs fine at 1/2 to full WOT. On shutdown gas is bubbling out the secondaries.

I then take the rubber handle end of a screw driver then proceed to bang around the carb in the general areas of the floats. This clears clears whatever was holding the float(s) open and it starts up and gets me home.
I finally got around to checking it out today.

I've gotta say that this Edelbrock 1406 AFB clone is the easiest 4bbl carb I've ever worked on. After pulling 3 clips that held the choke, accelerator pump and throttle linkages, removing the fuel line and approx 8 torx screws I was able to easily lift the top half of the carb off and access the "gut's" of it without removing anything else. The crud was visible at the bottom of both float bowls and easily cleaned out. The main jets are right there also but on a boss that lifted them 1/8" or so higher than the bottom of the bowls which helped to keep the crud out of them. The float assembly is housed on the top cover and the floats are very easy to check and adjust as were the float valves and seats. Checking the float adjustment is as easy as rolling a 7/16ths drill bit between the cover (with gasket on) and the bottom of the float(s).
I blew out the valves and housing passages and the main jets then put it back together. Even with the stock fuel pump the fuel bowls filled quickly and the engine started and remained running after the 3rd short cranking.
Then took it out on my usual 60 mile cruiise and it ran as good as it ever did.
Color me impressed.

I replaced both fuel filters, (one before the pump and one before the carb) in hopes all the crud is now purged from the system. We'll see.
The filter between the pump and carb was one of those chrome jobs and I should have changed it out when I replaced the fuel tank, fuel pump and before-pump filter but didn't. Thats probably the source of the crud that held the float(s) open.

Oh, on a side note, The Mrs was thinking about going on that cruise with me but decided to do something else and took a raincheck. Good thing, I'd have had a real hard time with her on that break down LOL....

Dave

Just when you think it's safe to peer into the HiPo forum I hit you with an update, and here I thought I was done with it LOL...

I've been wanting to hear what the Jimmy sounded like since the engine swap. In the cab it has a nice low rumble up to around 35 then the wind noise takes over. That is unless I goose it then the sweet sound of 600cfm of air being gobbled up by those 4bbls takes precedence. Sounds great but alas, no exhaust sound to be heard over the carb and wind noise.... 

So after putting it up for the day the daughter and SIL came by later that evening to drop the grandsons off so they can go to an after Halloween party as a couple of Grease characters. They floated an off the cuff request to drive the Jimmy to the party and I tossed them the keys. I thought they were gonna pass out LOL..... After some instructions and a fare-thee-well I finally got to hear those MagnaFlows proper. I likee.....
My daughter wouldn't let him open it up when they pulled out but I got him to when they came back.

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