First thing is to find a trnasmission that will swap in. Unless the 82 has a NP435, or castiron 4speed OD, not much else will work from that donor. The lighter duty F100-150 trucks had an aluminum SROD tranny that wont work. Later models(85-89), had the aluminum RTS thats a good choice if not planning any hardcore serious offroading. Unless it has the NP435, you will have to change out the mainshaft for it to work.
DO you know what tranny the truck has?