I´ve been researching some, gas is pushing $6 a gallon here. Not serious research, but have been picking up some possiblities.
Toyota (Land Cruiser) make a turbo Diesel with an automatic, IF the auto is the A340 or a variation there of, it might be possible to change the rear end (shaft and tail piece) from the AW4 with the A340 and use everything from the transfer back.
Don´t know how many of the Land Cruisers, if any, were shipped to the states, in diesel automatic. Mexico might be a good place to look.
The Renault Diesel has a sorry reputation, pretty common here in Germany.
Might be worth some reseach to try and find how many bolt patterns the Toyota motor has, the difference between gas, diesel and even fork lifts/construction equip. Seen many propane powered fork lifts.
Guess this belongs in the modified section.