the right tranni fluid?

ATF+4 is a superior fluid. Fully synthetic w/ more friction than Type F (what I used to use). It can't hurt your Torqueflite because the later A-413 front-wheel drive tranny (in my Voyager) is also a Torqueflite, almost indentical internally, and it uses ATF-4. I use Autozone's store brand since probably from the same factory and says "synthetic".

The only reason to use Dexron is if you really want to save $1/qt for inferior fluid. A lot of Chrysler V-6 minivans were messed up because shops put in Dexron since the owner's manual said "OK to use Dexron if you can't find ATF". It caused the lockup torque converter to shudder, wearing out the clutch plates.