Are the frames the same?
 

Hey y'all. We have a 77 three quarter ton chevy donor. We are wanting to build a 80 crew cab chevy. All of them for sale around here are 2wd. But we have been told that's the frames are all the same and drilled for 2wd and 4wd. Can anybody confirm this? Thanks

Re: Are the frames the same?
 

No, they are not the same. The front crossmembers are very different and the framerails themselves are shaped differently from the cab back.

Re: Are the frames the same?
 

I am in the process of converting an '85 crew cab dually 2wd frame into 4wd, for my '90 V3500. The 4wd frame is to hacked on, bent, and rusty to use. I'm using all the 4wd specific parts on the 2wd chassis. I can tell you while it is possible I do not recommend doing this. I'm already dedicated but had I known how much screwing around this would be I would have done it different.

The rails are shaped different in front of the front cab mount and my not provide enough clearance for the front leaf spring. The steering box mount is different between the two. The rear spring hangers are longer on a 4wd and the 4wd specific holes do not line up with the 2wd frame. The 4wd core support mounts are different and the holes don't line up with the 2wd frame either. Although, I believe the 2wd is a stronger frame because it doesn't neck down from 8" to 6" in front of the front cab mount.

Nate

Re: Are the frames the same?
 

After working on my frame I've decided to splice the two together at the front cab mount. The frames are to different in the front clip that it's the only way I see getting a usable frame from the two.

My front frame horns need a little tlc but the real reason for using the 2wd frame was because it has rust free straight not welded on rails. The front clip from the 4wd frame is still good.

Nate

Re: Are the frames the same?
 

I'll post some pics of my conversion in a day or so. Not bad, I robbed my stuff from a cucv. I built a engine crossmember from a tcase crossmember. Turned out great till it gets a Cummins conversion.

Re: Are the frames the same?
 

http://www.gm***************/forum/s...ead.php?t=2843
http://coloradok5.com/forums/showthread.php?t=82107

basically if you can use a drill and find a junk 4wd it will work