I have been pursuing my first build of my 1948 1/2 ton. I am to the stage where I need some assistance to not spend money I don't need to. Currently, I have a 10 bolt from a 75 Nova with 3.08 gears, a TH350, and a freshly rebuilt 250 that I am buying for $400. I have the entire body off the chassis and this is where I need help. Is the running gear I mentioned going to work well together? I plan on installing IFS while leaving the rear with leafs. The 250 is from a 71 Nova so the motor mounts shouldn't be too difficult, I am wondering if all this sounds like the right way to go or should I go a different direction. I could really use some advice, thank you.
Yes, the stuff you have will work together. Some small bits of fabrication may be required. Should be reliable and easy to drive. The more component specific advise will be along shortly. By the way, you can make anything work with a good welder and fabricating skills. From a small gas engine all the way to a big honking diesel. It’s yours, have fun with it.👋ðŸ»
Martin '62 Chevy C-10 Stepside Shortbed (Restomod in progress) '47 Chevy 3100 5 Window (long term project) ‘65 Chevy Biscayne (Emily) ‘39 Dodge Business Coupe (Clarence) “I fought the law and the law won" now I are a retired one! Support those brave men/women who stand the "Thin Blue Line"! Hug a cop! USAF 1965-1969 Weather Observation Tech (I got paid to look at the clouds)
I like the idea of the 250, my main concern is fitment and I would like to keep everything mechanical i.e. fuel pump, distributor, and fan. Is that going to be possible without major metal fabrication? I read on another post that the 250 block is really long.
The 250 is longer than the 216, and maybe slightly longer than the GMC inlines. You'll probably need to massage the radiator mounting position a little. Another sticking point will be the crossmember where the 216 bellhousing mounted- - - -the TH350 bell housing is a bit larger and shaped differently, so it will be difficult or impossible to get the engine/trans to fit at the right angle without doing a little whittling back there. DO NOT REMOVE THE CROSSMEMBER ALTOGETHER! It's also there to brace the rear of the front springs and add stiffness to the frame. Even if you do choose to use an IFS (Big mistake in my opinion) be sure to fabricate a dropped crossmember to reinforce the frame when you remove the original crossmember.
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
As you can see with your combination, unless someone has actually done it with those exact components, we can only give general swap advice. The answer is ALWAYS in the mock up. Then you will have specific questions we can answer.
"Going to work well together" is subjective. The motor, tranny and differential ratio lean towards highway cruiser more than breaking tires loose. The "direction" you go is your decision.
With all you are doing, (redesign of the truck mechanicals, suspension and drivetrain), you will have problems to work out, fabrication and some money to spend. As said, it can all be done. Has all been done. If these are the components you want to use, put them together and mock it all up. Clearances to: radiator X,Y and Z position, cross members, firewall, steering box, exhaust, body clearances..... an eye on pinion angle, motor and trans mounts, shifter, drive shaft yokes. Then lock it all in and wire it, plumb it, hose it and tail pipe it.
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. - William Penn
A 250 in an AD truck is a very doable engine upgrade but there is some cutting, welding and component relocation involved. I recently replaced a 250 in a 49 GMC and took some pics and made a few observations as I went. I'm no expert on this mod and welcome any corrections. I never got to drive it with the 250 but have driven 250 powered Chevy's back in the day and a 250 should have no problems moving an AD truck in modern traffic.
As stated the 250 is long and the bell housing taller, especially if it's an automatic so it won't fit without some mods. If you want to go with an automatic or more modern straight stick you'l need to change the rear and driveshaft to an open type. A popular donor is the 70's-80's Nova's. This will involve cutting & welding on the frame and axle housing. May have to have the driveshaft cut, rewelded and balanced. Due to the need to do it correctly it is a 9 on a scale of 10.
The radiator on a GMC AD is already setback due to their original OEM engines being longer than the Chevy's so the radiator on a Chevy AD will have to be moved forward. There's room in the radiator mount and it is a 3 or 4 on a scale of 10. A possible easy mod may be to change to a GMC AD radiator with it's built-in setback brackets. One would have to research that. The 250 will sit too low to use a mechanical fan so going with an electric fan is necessary.
Pic of how close the waterpump pulley sits to an OEM GMC radiator: PIC
Another pic showing how tight the engine sits in the bay: (Note the small 12" electric fab has clearance but is too small.A larger 16" fan would fit: PIC
A pic of the right side motor mount: PIC Left side motor mount: PIC
A pic of the firewall cut and also shows where the frame mounted motor mount brackets were welded. Also take note that the frame cross member that was located basically right at the front of the cab has been cut out to make clearance for the 250 engine and TH350 tranny. The replacement crossmember is further back under the cab: PIC Another PIC: PIC
Another shot of the frame mounted motor mounts. These are OEM clam shell lower mounts: PIC
You say the rear is from a 75 and the engine a 71 but what year is the IFS you're going to use? Either of these years came with a 250 I6 so factory engine mounts are readily available. There is a good chance the factory mounts won't work for the needed radiator and fire wall clearance but since you will have to fabricate a core support mount on the new IFS frame clip you may just have to make up a new core support itself which you can position for needed clearances. We do this on AD to S10 chassis swaps and it's not a huge chore. If you don't have a Nova clip yet the 74 and older ones are rear steer and a bit easier to hook up steering. DO NOT USE a Camaro/Firebird clip on an AD.
Care to explain yourself, since there are thousands of them on the road with great success. ðŸ›
Martin '62 Chevy C-10 Stepside Shortbed (Restomod in progress) '47 Chevy 3100 5 Window (long term project) ‘65 Chevy Biscayne (Emily) ‘39 Dodge Business Coupe (Clarence) “I fought the law and the law won" now I are a retired one! Support those brave men/women who stand the "Thin Blue Line"! Hug a cop! USAF 1965-1969 Weather Observation Tech (I got paid to look at the clouds)
In an instant---they are too d*mn wide. To keep the tires inside the fender opening you have to jump through hoops to get a wheel combination that will be inside the fender yet still clear steering components. The bright red 48 has a Camaro clip with shorter A-frames and control arms, to bring the tires in, and after a bunch of spring rate juggling it still rides lake crap. The flat red 52 has a Nova and everything bolts in place. You CAN make a toothpick out of a 36" log but why? The fellow is on his FIRST build so maybe he should use what works without a bunch of mods. Even easier is a Pacer IFS which BOLTS into place---Orange truck. And finally a 50 with the Mustang II which is engineered to fit---last picture.
If interested here are two ways to join the IFS clip to the AD frame; both #*&%v Camaro clips. To have the truck set just a bit lower than factory height mate the truck channel frame to the Camaro clip with both frame set level, first picture. To have the truck set low run the Camaro sub in under the AD frame, second picture. Orange and black truck sets less low than ones in previous pics.
Thank you guys for sharing all your knowledge. I decided against the 250, and ended up going with a SBC stroker motor. The IFS is from CPP and I hope everything goes well during the installation. I’ll be putting parabolic springs in the rear to soften the ride a bit, I was going to go 4-link but couldn’t justify the extra $.
Question for all the smart people out there. I have the frame stripped bare, the IFS crossmember welded in and for ease of use I’d like to turn it into a roller for moving it in and out of my tiny garage. Is there a good guess at spring perch angle so I can get the rear axle in? That way I can determine where my shock mounting crossmember needs to be welded. I’d like to have all the welding done before powder coating. In case someone has done the same setup before I’m using a 10 bolt 8.5”, SBC, and a TH350 with parabolic springs and the axle mounted on top.
Welding anything to a bare frame is a mistake. You will almost certainly end up with the wheel centers and the fender openings mismatched. If you want a roller, just set the frame on the rear end housing and C-clamp or bungee cord it into place. Then you can hope you put the IFS spindle center in the correct location. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Joe Hand, a regular contributor on this forum and a really knowledgible guy, has transplanted a 250 engine into a '37 Chevy car. He's made some parts for it that are real eye candy and he can probably tell you all about how a 250 fits where a 216 used to be if you decide to go back to the 250 plan.
On mocking up the rearend, you should first figure out what angle your driveline is at. My engine sits ata 5 degree angle to the frame. With that said, most vehicles have a 2-3 degree rake, so technically the engine/trans sits at 2-3 degree angle to the ground. Most rearends are setup with a negative1 to 2 degree to help compensate for axle wrap. I hope that helps.
I see you bought a CPP Ifs, I purchased their Economy crossmember last year. Anyhow, have you established a ride height? Off hand, it looks like my crossmember is going to lower the truck around 4”. I’m planning on adding some material because I don’t want it that low.
I haven’t established ride height yet, the crossmember was just welded in last weekend and I just got the frame home. It installed pretty easy, lot and lots of measuring and remeasuring then double checking before tacking and final welding. We installed the crossmember with a 2 degree angle front to back to help offset the rake from the rear suspension.
I figure the IFS like you said should drop it around 4”, the springs in the back should lower the rear between 3-4”. I’m putting smaller tires 26”, with the back a bit wider than the front. I am ok with the lower height as the front springs were totally flat and the rears we fairly flat from 12 years in storage with two motors in the bed.
When we were building/repairing round track race car frames, we used square tubing fixtures with caster wheels on them to roll unfinished projects around the shop. One bay was set up with chain anchors in the floor and jackscrew-type stands to support the frame, and the level floor was used as a surface plate baseline for all the measurements. We would chain the frame down level, and use a laser construction level on a tripod for precision height measurements. Places like Harbor Freight or Northern Tool have those lasers at bargain prices. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Just a thought, I bought new rear end saddles for my '52 that had, if I remember right, 1 1/2 inch offset to move my rear end backwards that far to center my rear wheels in the back fenders. Trucks I have seen that don't have that done drive me nuts.
Hello, I'm curious how you welded the CPP crossmember in? It seems you have to set the angle of the crossmember level to ground after you set the ride height. How do you set ride height before you have tires and wheels on? I'm thinking of going with the same CPP kit. The rear end in my truck is from a 59 Cadillac so the axle is bigger than 3 inches. I'm thinking of finding a 10 bolt to make my life easier, not to mention the brake drums for a 59 Cadillac are expensive! Thank you,
Hello, I'm curious how you welded the CPP crossmember in? It seems you have to set the angle of the crossmember level to ground after you set the ride height. How do you set ride height before you have tires and wheels on? I'm thinking of going with the same CPP kit. The rear end in my truck is from a 59 Cadillac so the axle is bigger than 3 inches. I'm thinking of finding a 10 bolt to make my life easier, not to mention the brake drums for a 59 Cadillac are expensive! Thank you,
Pretty much every set of directions I’ve seen state to set the frame at a 2-3 degree rake and weld the crossmember level to the ground. If you want your truck high in the back, set it at 3 degrees, if you like the saggy look, 2 degrees or less. I think I ended up with around 2.5 degrees when it was all said and done. The 2-3 degrees isn’t really a set in stone number. If you’re off one way or the other, it’s not the end of the world. Depending on how you set up the top mounts in relationship to it will affect your anti-dive but that’s about it.
Hi whitedog, have you put in one of these CPP kits? It’s says it’s a 2” drop which doesn’t sound that dramatic. My 70 year old leaf spring are probably sagging at least that much. I’m leaning towards this kit. It is affordable and solves a lot of my issues (with my truck).
Yes I have installed one. I don't have mine buttoned up yet. I need some shocks, springs, hubs, etc... I did a bunch of measuring and figuring before I did anything. I also bought a chassis design book so I could educate myself on suspension geometry. The CPP kit, actually will give you more of a 3-4" drop with the "stock" style spindle by my calculations. I don't want a low rider, so I added some material to mine and trimmed down the spring hats.
Very cool. Did you just hit your frame with a rattle can or is that chassis saver or something else? I think this may settle my decision. I really wasn’t looking to lower my truck and it sounds like an IFS will lower it. Something that surprises me is that in all the years people have been doing V8 swaps on these trucks, there doesn’t seem to be a straightforward solution or kit for moving the steering box. My whole steering wheel was moved like 4” to towards the drivers side window. Looks pretty hokey. I know there are some power steering kits that correct the issue but I want to be careful that I don’t introduce a bunch of wacky geometry.
I hit it with some Rustoleum and satin black enamel. I took a bunch more pictures, but the black doesn't show up that well. Anyhow, if you don't want a bunch of drop another option is buying a universal, uncut crossmember. You'll have to cut and trim everything yourself. With the particular crossmember that I have, it's what they call the 56" crossmember. If I had to do it again, I'd buy a 58" cossmember. I added 1.5" of material and notched the spring hats accordingly, but I can't go any further than that without the upper A arms hitting the frame which is why the 58" would be better.
Here's a couple good threads of a 49 using a JW Rod Garage 58" IFS. It's very close to being the stock height. He goes by Hampshire over at the 67-72 forum.
Looks lik you have a nice big shop...I’m in a two car garage. Why does Hampshires truck have the big crossmember by the firewall? Is that the original crossmember? I don’t have that on my truck and it looks like yours is gone too.
Fascinating stuff. I bought my truck with a MII crossmember already installed by a PO. The spring hats are even with the top of the frame (just about like Whitedog's) but it still dropped the truck 2-3" lower than stock.
Maybe they are trying to bring back the 90’s when lowered mini-trucks were totally rad.
In reality you're not that far off. Mini-truckers of the 80s and 90s have matured into the AD owners of today, hence the emphasis on air bag suspension and "laying frame." I have built bagged vehicles but now, having lived through forgettable fads from Donk hydraulics to horns that play "Dixie," I prefer to keep my truck free from trendy gimmicks. If you're always chasing the current trend, your truck will be obsolete before you're done building it.
