I have an opportunity to buy a 57' F100 3/4 ton. The guy cut the frame and put a short bed on it. I'm pretty leary of his butt welds on the frame but he said he has a 1/2 ton frame for it too. Do you know if the cab mounts are the same on the 3/4 ton as the 1/2 ton? What about the bed mounts, etc. There are so many variables here that I'm not even sure what questions to ask. Basically can I take the 3/4 ton body and put it on the 1/2 ton chassis?
The half-ton and three-quarter ton frames are the same. Springs are beefier on the three-quarter ton. Also, they have different rear-ends, probably transmissions too.There are 110" and 118" wheelbases (long vs. short bed), perhaps he shortened a long wheelbase truck to accept a short bed.
How long was it driven after he shortened it? Is the extra frame a long or short wheelbase frame? I' d have it evaluated by someone who is an experience builder that can tell you if the frame modifications were done correctly, or can be made safe. It's a lot of work to swap frames, maybe less to repair/ reinforce the one your cab is currently on. Good luck.
He did mention that the current shortbed truck has 8 lug rims and a different rear end. It was a long box shortened to accomodate a short bed. Infact, I think he said he took 8" out of the frame. So that would make perfect sense. I don't think he really drove it much after he shortened it, it's still a "project" truck.
He said he made a straight cut on the frame and but welded it together. Then he took from the 8" he took out and reinforced the weld areas. I guess I'd just have to look at it to see if it was done right or not. Thanks for your help.