That sounds very do-able. Since I'm going to have to do a little welding on the cab corners, I might as well pick up a little welder now. I'll also have to see what gears are in it since the owner does not know. Before committing, I'm going to check a few junkyards and see what it would cost me to pick up a differential case, an axle shaft, and a seal kit.
Does the frame taper out from behind the cab to the end of the bed? My measurements from perch to perch was 40 in., but that number gradually grew as I measured the distance between the leaf springs moving towards the back of the truck.
Also, do I need to do anything as far as the u-joint goes? The drive shaft seems to have been modified as it looks stock at the front but is not a torque tube setup. It has a regular drive shaft that connected to the 12 bolt.