Is there something wrong with the 1FZ engine in it? If not use it! Keep the auto and you have all the power you need - nothing against the 3B but putting it in the 80 would just turn it into a tractor in my opinion, keep the gasser, get worse mileage but you have all the power you need with less wiring, mod hassles. The fun part of that build would be modding the body.
Or.......... bring your 80 up and work on the real off roader - your 75 series. Bob the back end, cut as much of the frame as you can in front of the rear tires. Have a competent fabricator bend and weld a roll cage/deck for the back ( a friend here builds cages for race cars and tube chassis for porsches for the last 40 years - and does it for cash and cheap). Put a winch in the back - shortened 75, no turbo needed but add later for making it sound cool and you have the most agile little truck around.
You could even put the rad behind the cab with dual fans and mount an 8274 in nice and close making it even shorter, add an exo skeleton, coil the front and rear - or just the rear since the back end is modded you cut put long travel coil shocks - tons of fun!
Or take the 1FZ out of the 80 and put it in the 75! It would be a monster with that engine in it - check out the videos in South america with the 70's running that engine and tell me it isn't a great package
Only limited by time, money, and imagination.
