The Stovebolt Site Forums The Shop Area Driveline 1949 Chevy 3100 4wd swap??

Hello all, I’m new to this site. I’ve owned the truck for over two years now, and I can tell the 235 I have in the truck is tired, and so is the clutch and trans. It’s got the original four speed on the floor with torque tube driveline. I’m looking to swap from this power train to a 250(perhaps a 292) with an nv4500 and some kind of transfer case. My question is, what is the best transfer case/ axle combo to run that isn’t an insanely high amount of work? I’m fine with doing work but I don’t want the truck on stands for months. I’ve read that an ‘90 nv4500 will mate to an NP241 out of an 89 suburban. Will that work? Also, I’ve read that Toyota axles pre1985 will fit, but are there any other options out there? Preferably Chevy or gm if possible. I’m not afraid of getting axles cut down but I’d much rather avoid the extra expense. Any advice or input from you experienced guys? I want to keep the original frame; I may box it in the coming years to reinforce it. But for now I just want a full drivetrain swap to something I can enjoy driving daily. Right now I’m getting 7 mpg with the tired old 235... at this rate I’m saving money doing this work now than paying for today’s gas prices!

Welcome to the Bolt

Just swap your sheet metal onto a S-10 4x4, they make kits for all of the body mounts, do a internet search. If you search here on the Stovebolt you'll find lots of reading on this swap...all the engineering is already done for modern drivetrain with old truck look.

Mike B

I’m not looking to do an entire frame swap though, and I also don’t want ifs. I’d like to keep a kind of “retro” build look, as if someone were to build a truck like this back in the 70s or so. I want solid axles and to keep my original frame as nothing is wrong with it. It’s in great shape, actually still has what looks like factory paint on it in several places

Where I live the guys find an old rust bucket with a title and do a complete frame swap using whatever is commonly available from the local junk yard (salvage yard). Early 70's to late 80's Chevy or GMC. The wheels stick out past the fenders but appearance is secondary. The diesel guys also like a frame swap but use big truck fenders to cover the giant tires. On the weekends in the dry summer months they compete with each other running through the mud of a local lake bottom. It's all for fun. This type of modification I would consider as the #1 budget option.

After the first half of 1955, the truck frames and axles became wider so your are limited on 4X4 used parts that fit inside the fenders of an AD truck. Doing 4X4 on an AD that is in good condition, other than NAPCO, needs careful consideration towards resale value i.e. you don't want to drop a lot of $$$ into a truck that may not sell well in your area because of personal tastes in the truck appearance. If I was doing a 4X4, I would try to clone what NAPCO provided many years ago.

The stock truck 235 engine, 4 speed transmission and rear axle combo were designed for use in real work trucks. Out in the field on a farm or with the US Forestry Service (still used today) running over rugged mountain roads. Low speed and high torque. They were not designed for cruising the expressway running at 75 mph.

Yes I’m aware of the crazy torque these things have with the stock combinations, but my engine isn’t original to the truck. The trans and rear-end is, but both the engine and trans are pretty tired. I don’t have much sentimental value towards the existing drivetrain, or at least enough to want to put more money into it. I want to turn the truck into a nice daily driver that can perform somewhat like a modern half ton. I don’t want it lifted on stilts like the guys who use the 70s/80s frames, they’re wayy too wide I think. From what I’ve read so far it seems only Toyota axles from 85 and back would work. I’m just looking for input as to if I’m missing any Options. I’d like to be able to do 75 on the highway, and be able to go off asphalt every once in a while. That’s why I’m thinking an NV4500/NP241 combo with Toyota axles. Unless it would be smarter for me to go 3/4 ton gm axles and have them cut down?

I have read the '80 to '91 Wagoneer Narrow-Track Dana 44 is a good option at 60" wide. I thought about doing what you plan, but ended up swapping in the frame from an '88 K2500 to maintain the stock height. The stock solid front axle has a drop, you loose that when you put a solid drive axle in. Also look to match the axle with transfer case regarding driver side drop, or passenger side drop.

Before you get started, talk to your insurance company. The issue comes up if you modify stock parts (GM, Toyota, Jeep etc.) especially for braking and steering. A common one is bump-steer and the need for a different size or shape pitman arm. The best bad example I can think of is heating and bending a forged pitman arm. You may be liable if your modification fails and someone is harmed.

Yeah that’s one of my biggest concerns with the project. Right now it’s on historic insurance, but I plan to switch it to normal so I’m free to drive whenever. After more research, I’m not sure whether I even want a straight six anymore. To build a 250 or 292 to have similar power to a small block would cost much more money, and that’s the opposite of what I hope for this project to be. I’m still planning a 5 speed 4wd, but not sure whether to retain a six or go for the cheaper small block. Granted, small blocks have their own problems with fitting in next to the steering column and having room for a fan. Any input?

The biggest challenge for a front 4X4 axle is finding one which is not overly offset. The front ends of the leaf springs angle toward the center, leaving little room for the pumpkin to fit.
Jeeps are too far off center. The Early Bronco front axle might work.

If using a 292 or whatever six or small block Chevy engine, a NP-540 series 5 speed is very compact trans that will hook to a transfer case with some mix and match of parts if one does not need an OD trans.

Many people narrow Dana front axles by cutting the housing end and rewelding the ‘C’ shaped end on. Resplining shaft.
Ed

After doing a lot more research, I’ve started thinking about a tremec tko 5 speed instead of the nv3500s or 4500s because of the difficulties using the new venture gearboxes. Has anyone put a tremec tko 500 or a TR-4050 into an AD truck? Any advice someone could give on the subject?

Where is the S10 frame swap on here? I have my bed sitting on a 2000 S10 frame the wheels rub the bed . I just started unpacking the project from a divorce and a move . Wondering if I should just scrap the project or jump back in.

Check in the HiPo Forum. That’s where we discuss major modifications such as yours.

Several of us have used T5 transmissions, Wally. A 235 in good nick with a T5 with the right ratios and a rear end with the right ratio will work really well. Fact is with just a little homework you can set it up so it runs just like the original in the first 3 gears and then you get some overdrive-type benefit in 4th and 5th.

7 mpg sounds like an old Rochester. Going with a Carter could make 7 mpg history for you.

The T5 gearing, etc is a longer bit of information and I just sent this to another gentleman here. If you want to contact me via email, my address is: [email protected] I'll be happy to send you the same message.

My plans now have changed pretty significantly from when I first started the build. I scrapped the 4x4 idea, I’m having a 250 built right now for it (hits the dyno in a few days actually), and I’m keeping the solid front axle and upgrading to disc brakes. I’ve actually gone ahead and purchased an nv3500 already, I found one for only two hundred dollars so I jumped on it. The biggest difficulty I’m finding now, though, is what combinations of a flywheel, clutch, master and slave cylinder, and clutch pedal I can run. I haven’t been able to find much info on any of that kind of stuff, just that the trans can be swapped in. I’ll be mating what I believe to be a ‘93 nv3500 trans to a ‘68 Chevy 250. I have to find the right combos for flywheel, clutch, throwing bearing, and the hydraulic components that go with, but so far no luck. Anyone have any good info regarding the clutch or anything of the sort? I would greatly appreciate it, hoping to have this build completely done by january

S-10 4wd rear axles are somewhat wider than 2wd, however the bolt pattern will be 6 lug.

Ed