Last year I sold my 05 Chevy 3500 with the 8.1l and Alison 5 speed. I carried a 2001 Lance 961 (4000#) and towed a utility trailer (6000#-8000#). When I sold it, there were about 130,000 miles and it still ran great. If you're familiar with the i15 in Calif., approaching the top of the Cajon pass, it would slow down to 50. Other than that, it would pull without any difficulty. It was a thirsty beast getting a consistent 8.5 mpg at 55. Every 5 mph over that dropped about .5 mpg.
That said, I bought a Host Everest, and it would have been way too heavy for that truck. Not so much because of the engine, but the suspension, axles, etc. would have been drastically overloaded.
You statement that you want to be able to handle "any camper" with that truck is not realistic, but if you're looking for a camper in the 4000# (fully loaded) or less, it will be fine.