I'm not sure about the 4wd, but my 91 S10 2WD frame had lots of straight frame rail under the cab, which made it *very* easy to lengthen using 5 inch wide heavy steel channel. The channel fit so nice & snug in the S10 rails, that I could extend and retract it while fitting up my 1-ton long wheelbase panel body. There are pics on my page. For my 46, the full size newer truck frames put the tires out too far. I'd much rather have them in the wells, to be able to lower it if needed. The 4WD rear end is a little (4inches) wider than the 2WD unit and bolts right in. The 2WD rear rubbed the inside of the tires on the body. I did sort of a step-by-step on the page in my sig line. I will be adding more soon. I am hooked on the idea of transplanting S10 frames now. Cheers, MV
