I have a 78 2 wheel drive truck and a 79 4 wheel drive truck that I want to make into one the 4x4 is smashed in the rear and the frame is toast but the 2 wheel drive is in extremely good condition frame wise. Are the frames the same if I were to take the front axle and drivetrain from the 4 wheel drive truck?? Thanks.

 

Cross member and spring perches are different. You would be much better off finding a 4x4 frame.

 

the above is true but if you take them both down to the frame its not impossible to swap things over. It will be a fair bit of cutting and welding though. The most important bits are the front engine crossmember. Whats your plans for the truck? If youre gonna lift it a good bit, the crossmembers probably won't need changed anyway, and the spring perches might not matter than much anyway.

Also I should point out that I believe that some 2wd heavy duty trucks even in the late 70's had the narrower rear frame like the earlier 4wd high boy trucks.

 

I've got two side by side right now and they're quite a bit different but I don't see it as impossible, just time consuming.

you'll want to cut out the 2wd crossmember and replace it with the 4wd crossmember, as well as the sections boxing the front of the frame for the steering box mounting.

it will take some work because of the differences in frame shape.

Alternatively you could just cut out the 2wd crossmember and box the frame yourself and build your own crossmember in a convenient place and mount the 4wd motor mount towers in the right place.

The spring hangers will go on without too much trouble, just drill the holes in the right places.

 

Hey Guys,

On a similar note, I'm needing to know if a body swap is possible from a 74 f250 2 wheel drive will fit on a 77 f250 4 wheel high boy. Many thanks!

 

Yep. You'll have to drill out the rear cab mounting holes to fit the rear Highboy cab mounts, but on the bottom of the cab there are actually template holes to drill out. Also, unless the bed is from a camper special with a narrow frame, than the bed mounting holes will be different, but you can drill those out to fit the highboy frame. You should put a spacer in the newly drilled bed mounting holes to keep the bed from collapsing when you tighten bolts.

 

Many thanks. I'm finding it's a bit more reasonable/accessible to find clean body parts from a 2x's drive, and you can't beat the prices for a complete truck.

I'm trying to keep my overall costs down and have been seeing some great looking 2x's that don't require body work and/or paint. Given the pricing I've seen at LMC, etc, this seems a much better way to go, that is of course if the donor truck is in excellent shape.

With that said, is there anything else I should watch out for? I'm assuming I can pull the front fenders, grill etc as one piece which should match up to my 77. The only other difference I'm seeing is the tank set up. My 77 has dual tanks with one being in the cab and one in back. I see that the 74 has both fuel inlets on the driver bed side, nothing on the cab. Would assume there should be plenty of room to run the additional tank along the frame on my 77.

Thoughts?

thanks again

 

What kind of tank do you have in the rear of your 77 4x4, because if your truck is a highboy, than a tank was never made for the rear. Highboys only had in cab tanks because of the narrow frame in the rear. Mid year 77s things changed and so the 77.5-79 F250 4x4s weren't considered Highboys. So you could have a 77 F250 4x4 but not a Highboy. I'm not saying you don't have one, but it's odd that it would have a rear tank unless it's custom.

 

Great question and I've often wondered the same. I'll have to check on my axle tomorrow but the truck does have a jackshaft coming from the tranny to a divorced transfer case. Along w/ the overall ride height of the truck I was under the impression this was one of the indicators of a high boy but I could be wrong.

 

What is the VIN of the truck?