I have a 21 3500 with HO and the aisin, bout to turn over 100k, only issue ive had is the damn EGR cooler bit it at approx 65k. Dealer was useless in troubleshooting it, then took 5 days to replace, and then had an exhaust leak after the replacement.
Other than that, shes been bulletproof, and I do some hard driving. I wear out 50k warranty tires in about 22k lol. been abusing that warranty. tire guys aint happy.
Only complaint is 12mpg, as I drive alot of city. Missing the 16-18mpg on my 96 12 valve. bleh.
-j