From what I've gathered the diesels had their own specific trans since it's hydro clutch due to the location of the fuel filter interfering with the cable exit hole in the firewall. (Since I've asked most of the questions over the posts I've learned) However I think the tailshafts/Transfer cases are interchangable making 2wd vs 4wd swapping pretty easy between models. As far as the guts being interchangable I havent gone that far yet. I'd bet the clutches are different making the input shafts different.