First off the 7.3's are slow, even chipped and built with a built tranny. Not to mention the ride is crap, it's all bouncy, and I swear the steering on those trucks are like 10 turns lock to lock. To me they just feel crappy all around. As far as tranny's go, I think you can have problems with all of them. My dad had a 2001 ram with 200,000 on it and the fucker never had any problems. Body was solid, motor of course ran strong, and even the stock tranny was still pulling strong. And those were all hard miles, as the truck was always loaded or towing. I personally have had to tow two chevy's both with the allison in them because there "bulletproof" transmissions went out. So in reality all will have ups and downs