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Hi Guys,
I posted some info on the welcome page about my 49 3/4 ton chevy and my plans for it. I've been reading a lot of posts over the last week and may revise my original goals. If i drop the need for 4X4, it would really simplify a lot of things. Right now, i have access to a 77 3/4 ton 4X4 chassis with a SBC 400 with rebuilt Turbo350 trans and rebuilt transfer case and matched front & rear axles, 3.73 in think. Problem is that the width of, at least, the front axle is almost 10 inches wider than the stock 49 and the frame in the 77 is also wider, if i remember, 8 inches wider than the 49. So, there would be a lot of work getting the axles under the 49 bodywork. I'm sure i'm going to find the same situtation with the rear axle.
Now if i loose the need for 4X4, i think it would save a lot of fabrication in just getting the drive line updated. I've especially been reading about swaping in a 472-500 caddy engine. That engine should provide all the necessary power/torque to meet my towing needs. I could still have an auto trans and could install some form of IFS, frame clip or IFS aftermarket kit. I do not want to go the s-10 route as i don't think it would stand up to the towing. I would like to hear from you guys if you were doing a project like this. Thanks,
Mike

Mike welcome to the Stovebolt!

I'm currently building a 1955 1st GMC 1-ton to pull a trailer. So aside from a slightly different cab and 12 inch longer wheelbase, my project is very similar to yours.

You don't say what the trailer you are pulling is, or where you expect to pull it. For a number of years I used a 454 powered 1-ton 4 wheel drive to pull my 7,000 pound trailer. I crossed Wyoming able to pass at will and went up Marathon Pass with ease with that setup.

To me that sets the standard for my project. Actually I want to be able to pull 10,000 pounds at 75+ across Wymoing (lots of grades on the freeway) and then run up something like Marathon without having to slow down. My now gone 454 powered pickup set the standard.

I have a Cadillac 500 with TH400 and have installed a GM 14-bolt rear with 3.42 gears. Next step is the IFS from a '72 Chevy C20.

The GM 14-bolt is what GM uses under many 3/4- and 1-ton trucks. I also have a Dana 70 HD which is GM's other choice. I went with the 14-bolt because I like the gears it has and because it fit nicely. My Dana has 4.10 gears which would be better for starting a load, but spin the motor faster all the time and I felt the Caddy motor has the torque to move the load but would be happier turning a little slower.

The torque band of the Caddy motor with those 3.42 gears mean I'll cruise comfortably at 60 to 80, and should have enough to start any load I have any business towing.

The '72 IFS gives me disk brakes and power steering without some of the problems that come with converting the straight axle. It also allows me to remove the bellhousing crossmember without worry over structural problems.

The combination of the '72 C20 IFS with the newer 14-bolt gives me modern brakes enough to stop the truck with load.

I'm happy to find someone doing a similar project and would be happy to dialog about the choices I've made and what the pros and cons of each might be.

I have another suggestion for your towing '49:
Why don't you look into the modern 6.0 liter engine from current Chevy/GMC trucks, and trans?
New 1-ton trucks use this engine, they give you modern reliability, good mileage and, rated at over 300HP, they sure haul! This engine is also smaller than a big old Cad, and even easy to mount if you use a front clip: either an aftermarket front clip can be bought with the right motor mounts, or an older V8 clip (Camaro, for instance) just requires a pair of engine mounts adapter plates. Easy!
The electronics part is also easy (yes, really!): you can have the OEM harness modified or buy an aftermarket one (I have used a place called Speartech for this, great guy!).
You could even use one of those newer 6-speed auto trans, or just the 4L80E (which is an electronic TH400 with OD).
Old engines are cool, but you need power and endless reliability (especially for heavy use), you can't beat a modern engine!

OldSub - Thanks for the reply. I've been to your web sites and read a lot of what you have posted. Lots of food for thought. I also frequent the H.A.M.B. alot and have looked a lot of threads about the 472-500 Caddy engines. Do you have any recent pics of your project, engine and trans install? Can you tell me more about the IFS C20 install? How is that going? Would it require a lot of fab to get the front tires inside the fenders? What is the width, wheel mounting surface to wheel mounting surface for the C20? Is it a 4X4 IFS? About towing, i've got a 16 foot flatbed and a 20 foot enclosed trailer. I'm just guessing, but i would like to be able to tow up to 9 - 10k. I think the most i've towed with my 97 GMC is around 6.5k or so. Is your truck going to be a dually? Thanks

WAVE1957 - Thanks for the reply. I have not firmly decided on engine choice yet. My 97 GMC has a 350 and 4L60e and the trans made it 154K miles before needing rebuilt. It blew out that sun shell part. This 6.0 engine you mentioned; it's not a diesel is it? And this electronics stuff, well, my biggest problem with that is how do i diagnose a problem when something happens? I really want to keep by dash simple and use original gauges, but updated with new internals, maybe a couple extra gauges like trans temp and such. I don't have any of the programmers or diag tools in my toolbox. If my GMC throws up a check engine lite, i've got to head to the dealer. I don't like being unable to troubleshoot for myself. Now with all that said, these computer engines sure do run cleaner and sometimes do get better milage. And if it ends up being cost effective, more dependable, and a cleaner install, i'm definitely listening. Thanks,

And for both of you; What about that rear engine crossmember issue? How would each of you deal with that? I'm guessing that it would have to come out with the drivetrain that you suggest.

Thanks for the info,

Mike

Mike the most recent stuff I've posted on the 1-ton project is on my Maxwell Garage site. I'm trying to move all my project stuff there from the OldSub site as if that matters to anyone but me...

I too have read much of what is on the HAMB about Cadillac motors and I check stuff at a number of Cadillac forums too. My current plan is to run a dead stock '74 or '76 (I have both) 500 with HEI and the stock carb. The '74 motor has the Eldorado oil pan and I may have to move it depending on which motor I actually use. I've not yet built mounts and have only mocked the motor up in place to check fit. Right now its on the floor ten feet away from the frame.

I'm not sure what to tell you about the IFS install. The '72 is not a four-wheel-drive. In those years 4x4 were all live axle designs on full size Chevy trucks, the IFS version started in '88. I'm basing mine on a '72 because I have one. The '71 to '87 pickup and to '91 or '92 Suburban are all the same design.

If you look around here you'll find I started a thread trying to find anyone who has made the swap and actually drives the finished truck. Lots of people quote Steve Andereggen Jr (I may have butchered the spelling--sorry Steve) about his conversion, but he ended up selling that frame and starting over with a straight axle. Once I learned that I contacted Steve directly (he lives in Oregon) and spent some time in his shop learning what he felt were the challenges to making the conversion work.

I then tracked down another guy who has a '50 GMC 1-ton with a Cummins Diesel and an IFS similar to what I'm planning to use. I knew he drives his because I'd seen it going down the freeway. Turns out he performed the swap something like ten years ago, and has driven it to Arizona (from Washington) each winter since and to and from New Hampshire (or someplace like that) every other summer.

Rashly assuming he is telling the truth clearly the IFS conversion can be make to work correctly. Since I spent a few hours in his shop looking at various projects he has done I feel his stories are credible.

My basic summary of how to do the IFS swap correctly is to carefully locate the IFS on the old truck frame so it is setting in the same relationship to the road that it did on the donor truck. Then make sure the steering box and idler arms are both located in relationship to the IFS exactly as on the donor.

Its all easy for me to say but the truth is the frame is on blocks in my shop and the IFS is setting out back still attached to the original frame. I hope to change that in the next month or so. Unfortunately my weekends have been busy with other things recently, today I'm changing the CV joints on the wife's Subaru.

The bellhousing crossmember is not real important once I convert to IFS. I'm thinking I'll replace it with an x-member type transmission mount, that will come forward to where that crossmember is today and extend back to the existing k-member.

The trucks I've seem completed did not get the wheels completely under the fenders. Some guys have narrowed the IFS. Others have used wheels with lots of negative offset. I'm thinking I'll widen the stock fenders to cover the tires though I've not completely rejected using fenders from a big truck instead.

I originally planned to build this truck as a dually, but have changed my mind. Part of it is the front suspension issues, and part of it is that I can't find good tires that will fit the old style 18 inch dually wheels. Since I can't use those wheels I've decided to go a different direction.

I agree with your aversion to using a modern motor. I have some computer controlled cars and they are just not as fun to work on and trouble-shooting them is a pain. Someday I'll get over that, since every few years I end up with another EFI car, but this truck will be carburated for the imediate future. I do have a TBI 454 that I've considered using in this truck, but the 500 Cad seems more appropriate for an old GMC...

I need to get back out in the shop and finish the CV joint project before my wife wants her car!

I've been researching Chevy pickup IFS swaps onto these trucks for a while. Just minutes ago I returned a phone call from a guy who contacted me out of the blue about some parts. In conversation it turns out he has a '53 Chevy 1-ton he recently converted to an IFS.

Tomorrow I'll visit his shop to check out the parts and look that truck over. If it seems comfortable I might offer to drive it just to get a feel for what its like.

I'll take pictures and share whatever I learn.

"Wave1957- Thanks for the reply. I have not firmly decided on engine choice yet. My 97 GMC has a 350 and 4L60e and the trans made it 154K miles before needing rebuilt. It blew out that sun shell part. This 6.0 engine you mentioned; it's not a diesel is it? And this electronics stuff, well, my biggest problem with that is how do i diagnose a problem when something happens? I really want to keep by dash simple and use original gauges, but updated with new internals, maybe a couple extra gauges like trans temp and such. I don't have any of the programmers or diag tools in my toolbox. If my GMC throws up a check engine lite, i've got to head to the dealer. I don't like being unable to troubleshoot for myself. Now with all that said, these computer engines sure do run cleaner and sometimes do get better milage. And if it ends up being cost effective, more dependable, and a cleaner install, i'm definitely listening. Thanks,

And for both of you; What about that rear engine crossmember issue? How would each of you deal with that? I'm guessing that it would have to come out with the drivetrain that you suggest."

This 6.0 liter engine (which is 364ci) is a gas engine, available in 2500HD and 3500 Chevy GMC trucks; the biggest engine is actually now a 6.2 liter, around 340HP, but 6.0 a couple of years old are quite common in junkyard.
I understand your worry about maintenance, but these trucks are surprisingly reliable (first tune-up after 100000miles...). It is also a question, if you worry, to drive with a diagnostic tool with you instead of a screwdriver!... And there is still a lot of stuff bolted on the engine, not everything is electronics-only! There would of course be things for you to learn and adapt (fuel system, for instance), but that is hot rodding, too! Try the LS1Tech.com forum, in particular the "Hybrid" section (not the lectric ones, for vehicle that did not come from the factory with an LS engine!).
The aftermarket covers very well these engines, they are covered by great forums, you would find a lot of support for your install. This family of engines (often called the LS engines)started as Corvette engines (with aluminium blocks) then evolved into trucks (with cast iron blocks). They are not anymore some exotic thing... You should even be able to find engine mounts/headers... specifically made for your truck (although I do not know this for sure).
As for rear trans crossmember, I do not know your particular vehicle but when I put a 6.0 liter with 4L80e trans in my '70 Impala, I just moved the original Impala trans back a few inches using a pair of L bracket; the crossmember just needed 1 hole drilled.

Wave1957- I went to that LS1 site you mentioned. There sure is a lot of neat stuff guys are doing there. I'm still reading a bunch of threads and trying to get a feel if this is a direction i want to go. But it IS interesting.

I do have some parts around the garage i could possible use:
carburated 400 SBC with rebuild turbo350auto and rebuilt transfer case.
77 4X4 front and rear axles
used turbo 400 trans/needs rebuilt
327 short block SBC
t-10 4-speed
as you can tell, i lean toward the Chevrolet line of products
And i've fot a line on a 454 builder engine and found a 472 caddy on craigs list for $300
So, here's part of the challenge, i'm financially challenged (that means unemployed) and trying to sell our house and half moved to our new home in Kansas. The house is a real fixer upper, in fact, i got it for free. I'm selling foo a lot of posessions to cover the cost of moving and to get truck rebuilding income. So, i want to try and be thoughtfull with this project.
I would like to keep and use the original 49 truck chassis. With my towing requirenents, what do you guys think would be a good choice for a rear axle, one that will still fit under the rear fenders? I have thought that i could add a 1 to 2 inch filler strip in the rear fenders to gain some width. I do not want a rear dually setup. Generally speaking, are 3/4 ton rear axles wider than 1/2 ton rear axles? I'm going to tru and get the rear of the 49 jacked up, wheels off and measure flange-to-flange this afternoon. Thanks,
Mike

Sunday I looked at a 1-ton with a 350 Chevy and TH 400. He had removed the bellhousing crossmember, installed a pickup IFS, power steering and power brakes.

He has only driven it a few miles because he hasn't sorted out all the brake issues yet.

OldSub- What was the IFS from? Did he have to take any metal out of the center to shorten the width?


I finally measured the rear axle wheel mounting to wheel mounting - 62 1/2 inches. So, now i'm looking for a 3/4 ton, possible 1 ton rear axle 62 1/2 inches wide. I really would like to find one with 6 lug mounting and disk brakes. Anyone have any ideas? Like i said earlier, i could add 1-2 inch filler strips to the rear fenders to get some more width, so a rear axle 64-65 inches wide could possibly work.

The IFS was from an '87 3/4-ton Suburban but would be basically the same as any '71 to '87 3/4-ton Chevy or GMC pickup and a few more years in Suburbans.

It was NOT narrowed and the wheels did not stick out from under the fenders. However this truck is a dually and he has dually type wheels on the front of it.

I put some pictures on my web site. '53 Chevy 1-ton dually with IFS conversion

For a time in the late 80's and 90's GM produced 3/4-ton pickups with 6-lug rears, but they are not full float so they aren't the best option for heavy loads or towing either one. I don't know if they had disk brakes and now that you ask I don't even know if the '91 I have has rear disk or not.

What wheels and tires do you want to run? You may find that a slightly different axle width will be best with your preferred wheels and tires.

Thanks OldSub. I checked out all the pics of the 53 IFS conversion. Too bad some of them were so out of focus. I'm trying to be on the lookout for an 71-87 3/4 ton truck.

Just curious, has anyone ever narrowed a IFS and installed it in an AD series truck? How did it turn out?

The rear disks didn't come out until they GMT800 chassis came in '99. Those were only on the 1/2 and light 3/4 (semi float) ton trucks. The Tahoe and Suburban got them in '00, and the C6P 3/4 ton (full float) and 1 tons got them in '01.Side note, the C6P 3/4 ton and 1 ton trucks used 2 different fear axles, depending on which engine was specified. Base trucks with the 6.0 gas engine got an updated version of the 14 bolt 10.5 ring gear diff that's been used since '73, Duramax and 8.1 gas trucks got an 11.5" ring gear rearend, whcih I beleive may have previously been used in the 3500HD 1.5 ton GMT 400 body trucks.

Longbox55/Bill, Thanks for the info. That C6P 3/4 ton axle might be what i'm looking for. Do you have any idea on the width, wheel mounting surface to wheel mounting surface? Or, is there any way or site online where i could look up this sort of information? Thanks, Mike

Hey Guys, I've got a line on a 402 Chevy truck short block. What do you think/know about these engines? Will 396/427 heads bolt on? Peice is good but i don't really know much about these engines. What sort of torque would one of these put out? Going this route would keep my chevy all chevy. Thanks,
Mike

I don't have the widths, but once you get past '00, the axles get rather wide, even the '88-'00 axles might be a bit on the wide side, especially with the 4x4 version. 2wd should be ok, though. Also, the basic axle is the same from '73-'00 on 2wd, so that might be the best option. If you wan the rear disks, the later axles brakes should be a bolt on, I'm esonably certain the mounting flage is the same. Or it could be easily modified to fit. You would need to scavenge the appropriate brackets froma disk brake truck, though.
On the 402, it is essentially a bored out 396, stroke is the same. So yes, the 396 and 427 heads will work. Torque output should be fairly decent, perhaps a bit more than a 396. Cam selection would have more to do with that, though.

If you are still wanting a 4X4 check out 3/4 ton jeep pickup's from the 70's. One of the locals put a 54 pickup on a jeep running gear and it looks like it belongs there.

if 4x4 is the way you want to go there are a number of options ,mid to late 70`s jeep wagoneer had a dana 6 bolt front axle with a 60" wheel mount to mount width, to match the front a rear axle from a 96 97 honda passport also uses a dana 44 with disc brakes, or a front axle from mid to late 70`s jeep cherokee chief has width of 64" to match the rear use a 98 to ? honda passport also with disc brakes, some rears came with locking diffs , the jeep and chevy front axles have the same roughly 32"center to spring

Have been looking over craigslist and seems 454s are more available and generally better priced. Two options here:
73 3/4 ton 2wd pickup with turbo 400 trans, rebuilt 454, looks to be in good shape and should be drivable for awhile asking $1600, OR 454 complete with all accessories and 700 trans with 60k miles out of wrecked 86 motorhome asking $800.
First option has complete drivetrain and is driveable and should be able to resale all sheetmetal when drivetrain removed, second option is 1/2 the price but no rear axle or front IFS. Either way will be tough squeezing out the bucks but the first seems to make more sense. What do you guys think?

That 700 trans in the '86 would scare me. You'll get some debate on this, but the 700r4 isn't really up to a big block with a heavy load.

Michael- I've been watching this post since it started. I like your concept of keeping you 49 heavy duty. That 700 is not good for a work vehicle. Pick up the pickup with the engine and trans, as well as the front suspension you need. Your truck will not easily swallow a small-block, much less a big block with stock suspension.

Devin

Well, i'm back with some more questions. But, before the questions, i just gotta tell you about my latest score. We have a friend who has a rental house out here near us and asked me if i could cleanup some of the mess left by her last renters. The renters were assholes anyway. Sure, i'm unemployed and could use a couple of bucks. She just wanted all the 'junk' out of the garage and off to the dump. There was about 4 pickup loads. Underneath a pile of cardboard boxes and dog food bags and other trash was a 454 on an almost new heavy duty engine stand. No carb, starter, or exhaust manifolds, but other wise complete. I told her i would do the cleanup for free, she still gave me $50 for gas money. Yahoo, everybody wins. Engine looks to be in average shape, rod and main bearings were standard, but wore out. Anyway, it looks like the engine for my 49 truck project has been found.
Now a question...
FRAME - I havent read anything about anyone doing a body swap to a 71-87 truck chassis. Why, is the frame too wide to mount the body? I'm not going to be using a S-10 chassis because i want the 3/4 ton capabilities and want to tow a 20-24 ft trailer, 8,000 - 10,000 lbs weight. S-10 just won't cut it. So, what are your thoughts about taking the 71-87 chassis 2 wheel drive and doing a front frame clip swap to the 49 chassis? This route, i could have newer front IFS and a easier engine swap of the 454. And the 49 cab would mount in its original spot.

Thanks,

Mike

This swap has been done, and some of those who have done it claim it works real well. The frame is only a little wider than your stock frame and getting the body on it would not be a big challenge. Aside from being a lot of work, the problem is that the width of the axles is wider. The wheel mounting surfaces are enough further out from the center of the frame that your challenge, especially in the front, will be getting the tires under the fenders.

Rather than clipping the frame a number of people have removed the IFS crossmember and bolted it to the older frames. In the area where the crossmember needs to bolt up the newer frame is about 1-1/4 inch wider than your '49 frame. I've seen the swap done by narrowing the crossmember, which helps with the track width problem, and by using spacers between the frame and crossmember.

From what I've seen the touchiest part of this swap is locating the steering box and idler arm correctly. If you do not position them in relation to the crossmember just as they were on the donor truck you are likely to have bump steer problems.

The advantage of taking the clip approach is that you can keep everything in its original location. The disadvantages are the same as for any clip project.

If you search my posts here on the Stovebolt you'll find a thread where I asked if anyone had one of these IFS swaps that was finished and on the road. At the time no one responded who owns a finished and driving swap of this type.

You will find reference to Steve Andereggen Jr and his swap. Steve Jr had bump steer problems and has since gone back to a straight axle on his project. I've met Steve Jr, seen his truck and his pictures, and feel I understand the problems he encountered. From his experience I emphasize careful placement of the steering box and idler arm.

There is a truck I've seen on the road actually running down the freeway with this swap. It took some doing but I found the owner and managed to spend a few hours with Joe talking about his swap and how it works. Joe is a guy in his later 70's who does not own a truck newer than 1950. He tells me his drives just like a new truck. I'm a little sketical of his claim because I'm not sure he has ever driven a new truck, but the evidence all says he has driven his tens of thousands of miles over the last ten years, and that his swap was successful.

Joe had wheels modified for the front of his truck and they still stick out about half an inch outside the fender on both sides.

Just recently I met a guy who lives only a couple miles from me who put the same IFS crossmember under his truck. His is a dually and by using 1/8th wheel spacers he was able to fit the stock 18-inch dually wheels on the IFS and inside the fenders. He hasn't finished his project and has only driven it a few miles. He does like the way it drives.

I've not gone back and reread this thread. I'm sure I've mentioned already that I am building a 1-ton to pull a trailer. I'm using a '55 1st GMC frame with a 14-bolt GM rear and a '72 C20 IFS. Today the 14-bolt is mounted but the IFS is five feet away and I doubt it will get any closer during May because of other commitments I have. I'll run a 500 Cadillac in mine, but conceptually we're doing very similar things.

My front wheels and tires will stick out too far. My plan is to mock up the cab and fenders once the IFS and motor are in place, choose wheels and get them in place, then modify the fenders to cover. I expect to use four fenders to make two, basically widening the fenders an inch or two on each side to get enough width. This will not be a trivial exercise.

I'm not convinced the S-10 frame is not stout enough for your propose, but would agree that the suspension and brakes that come with the S-10 are not adequate for towing the kind of loads you want. Changing the rear would be relatively easy. It may be possible to increase load/brake capacity of the front but I've not heard of anyone doing it and don't know how to approach it. But I don't like to extend my ignorance of how to do something to a conclusion it can't be done.

Are the pre 71 IFS any more narrow than the 71 and later units? Could i use, for example, a 65 3/4 ton IFS and then use aftermarket parts to get front disk brakes for this project?

Mike

I'm not aware of any disk kit for the early 3/4-tons that doesn't convert to 1/2-ton brakes at the same time, so that would argue its not an option. Last time I looked it was in response to someone else's similar question and I could not find anything.

But aside from that issue, if they are narrower its not by enough to solve the problem. They are almost interchangeable, one truck to another, so the difference would be in spindles and hubs and isn't likely to amount to much.

I beleive that the '63-'70 are only about an inch or so narrower in track width, and that's mostly in the brakes/spindles.