Originally Posted by PNW_Steve
No driveshaft work needed on the RE. To significantly shorten an FE or CE may require shortening driveshafts.
I think OP wants to shorten a FE behind the drive axle but it was suggested a midship cut in an RE. Admittedly I'm less of a fan of a midship slice and splice - it seems less complicated but more risky cutting the middle of the truck frame. There's also no driveshaft but still plenty of other stuff like fuel and air lines, electrical, and transmission controls to contend with in a midship cut.