I have a 2001 dodge 2500 with a 5.9 liter and the tranny is crap. The stock dodge transmissions are natorious for failure. What would a good aftermarket transmission swap for this truck.  

This may not be what you are looking for but I have a 98 Dodge 1500 with the 5.2L(318 CID) and the 46RE tranny. I swapped it out with the earlier 47RH from the 94-97 3500's that had the diesel or the V10. In 94-97 the 15/25/3500's had hydraulically controlled trannies, in 98 the switched to the electronic versions that were not as reliable. Hope it helps. I have a second 98 1500 that i am currently looking into swapping the auto out for a 5 or 6 speed manual. Its gonna be an off-road only truck and the auto wont last long.