Just got done dropping a '47 KB-6 cab onto a '78 Chevy 1 ton van chassis. Fits, but barely. Didn't channel - making more of a work truck. Van chassis is really odd - doesn't really have frame rails - more of frame 'U channels'. LOTS of torch work to get the cab off - had no idea the cab was welded to the chassis. The van chassis is from a camper - used it as the basis for this as I bought it for $300 and sold the AC and awning so it was basically free. Still need to fab cab mounts tomorrow - looks pretty simple with how it worked out. ScottInIowa
GM vans are unibody, but the cutaway van has more of a chassis to it - that's what they make campers and such out of. I've had a couple of regular vans now and the "frame" is just a deep C-channel welded to the floor all the way back. One good thing, though, the entire front crossmember unbolts, so converting one back to a 3/4 ton is easy. The shocks are even the same. 3/4 and 1/2 ton are 5x5 pattern and run a 10-bolt rear, too. I can't imagine one for this conversion, though. The steering is going to be a bitch unless you move the box, the van column uses two U-joints so it's aimed straight down to go into the box itself. Maybe change to a pickup truck steering box? Will probably have to make holes to mount it with.
I am NOT an engineer, but im not 100% sure that using a unibody "frame" as frame is a good idea. what makes a unibody strong is the fact that that u channel frames are one w/ the body, if you separete them and mount them like on a regular chassis they will fold. Still, i love the steering wheel on the engine bay, thats thinkin out of the box, or actually, out of the cab
Yea, the frame is...interesting. Gonna weld a plate back on the top today. This steering column only has one 'rag' joint. Realized last night I'll need a second U joint or the steering wheel will be really angled in the cab. Stopping at the race car shop tomorrow for U joint and steering shaft.
Gonna be a bitch to steer that puppy.......lol Looks like it might work, but a lot more work than starting with a more traditional chassis, say from a pickup
rumble seat for driver in the engine compartment? innovative idea. wait who will brake and accelerate?
That is a funny pic with the steering column ahead of the firewall. A simple U-joint at the box and then run the steering shaft above the exhaust (you will need a short column) will work fine for the steering. I agree, not too sure about the unibody "frame" worthiness without the rest of the body attached? Maybe run some simple rect tubing along the channel for reinforcement? I just don't know how strong that remaining frame is.
If you weld a plate across the top of the U-channel, you'll have something not all that different from the "top hat" style frames used under '49-'54 Chevys, that is pretty much how they were made, a U-channel with a plate welded on top.
just move the cab forward until the wheel fits into the cab. make a cab over out of it. its already fucked up.
Unibody subframes are usually also thinner than actual frames, so toppin it might only solve part of the problem, but then again, i never sen these van unis and might be diffrent.
GM van steering columns, at least 80s-up ones, have two U-joints in them - one right at the box, and one up higher at the firewall, so the column can turn about 75 degrees total. It looks like yours has the box angled back further, so maybe you can get away with one, but I'd do the same for that deal - put one at the box and another one somewhere inbetween. Or, honestly, find a regular pickup truck frame and start over with that. You have a good motor and trans, so you can buy one that doesn't run or has no engine and save a few bucks.
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