One thing I found on my 3 previous Dodge Cummins based trucks (2-92's and 1-'00 all A/T's) was that when I towed they wanted to get hot. Not just the trans but the engine's too.
This '93 with the 5-speed has been treating my real good so far.

 

I have an auto and it seems to get better by the day. The more i "break it in" the better it grabs when i need it to. I just modified my fuel curve and that seemed to do a LOT, i can chirp 3rd if i don't let off a medium pedal. 2nd chirps even when i baby the throttle, plus i can drink n not spill my morning beverage.