The 4wd stuff will bolt right in, no trouble at all. Your only aggravation will be swapping the pedal assembly out and installing the hydraulic clutch master cylinder. There is a late model clutch pedal assembly and a early model clutch pedal assembly, but I think the transition year may be around 87, but I am not sure. Will the hydraulic pedal assembly bolt right in your truck, which would have originally had a linkage system if it was a manual? I am not sure of that either, someone probably knows about this though.

Some people do this swap in stages. They will take the 2wd frontend out and install the 4wd axle, and drive it around like that till they get a chance to swap the tranny/transfer case in.