ok with the ford of that era you have quite a few choices one is the Borg Warner t18 a good rugged transmission great for haul four wheeling it has four gears 1st is a granny no over drive they use the same bell housings the only mode you might have to do is take the transmission bracket out turn the bracket around you'll see its not a straight bracket its got a bulge in it on most trs setups the bracket bulge is facing toward the front of the truck just take it out you'll need a 18mm deep six point socket and a 15mm wrench then you have the crappy mazdas that came in that era you can also toss a new process in there