Go for it!
Transmissions are not that difficult, an automatic is easier than a standard in my opinion. Get a good tech manual if you don't have one. Just check all the planetaries, thrust bearings, bushings, pump, valve body and flush everything thuroughly, Be sure you get the pump haves aligned correctly when reassembling if you don't have a pump alignment band (or a really big hose clamp) you can use the trans case, by turning the pump over with no oring. Better to use the band but the case will work Ok.
Good Luck,
Bill :wink: