I have a 1500 HD. Heavier spring front and rear. 3.73 rear and tranny cooler. It has the 5.3 and runs well. I have towed my 33 Fountain on a triple axle aluminum Performance trailer. It tows OK, not great. It is a little over the suggested rating and in my opinion, at the practical limit for the truck.
I don't tow hundreds of miles, typically around 15-20 one way. For that it is fine. It may be overkill, but I change my tranny fluid every two years (approx. 20k miles).
Mine is a 2000, and I love the truck.