I'll have to dig up the actual number of inches I had to shorten the frame but it was about 16" inches I think. I cut the sections from just in front of the rear wheels then used the sections I cut out as the plates I used to hold the two frame sections together. I drilled holes in the plate and bolted it together. Once I was sure the frame was straight I welded it up. I had to cut out sections in the fire wall to make room for the V8 banks and then welded up new covers to fill the holes.
I bought a non-running Ford Ranger for $150, an 1989 model year I think, and cut off the rear of the bed and welded it to the rear of the Bronco that had the upper portion and rear section of the rear cut off. I welded steel sheet to the bed rails and up around on the newly removed roof. The rear fender wells were cut and narrowed to give more usable bed width. A much better aluminum radiator was fitted which required trimming around the radiator supports along with lowering the top of the lower support. The radiator is for a Ford Explorer, I'll have to look up the model year. Here are a few pics that are on my computer, I'll have to load some more later from my phone and take a few more as well.