To swap to auto from manual, don't forget to change the radiator (no trans cooler in a manual truck radiator) and run the trans lines to and from the radiatior. You can use an aftermarket floor shifter so that you don't have to swap the steering column for a column shifter, pretty easy.

Keep the NP203, nothing wrong with it and the best Fulltime 4wd case from the '70s, by far (I currently have two of them).

I have an extra BB auto 4wd truck that I'd like to sell, as well, but I'm in IA and probably a little far for you...although it would have all the necessary parts for your swap...

JS