I'm kinda new to diesels, except for the ones I drove in the military. I bought a camper earlier this year that weighs 6500 lbs., we quickly found out that with it loaded I needed more than 8000 gross to pull safely. So now I am looking for an upgrade. I am looking at all 03'-07' 4x4 5.9L crew cabs, but leaning a lot toward 04' and 05'. I know the horsepower and torque went up in 05, and understand they got quieter also. Is it such a nite and day difference to go with the 05, or will it not be noticeable enough to worry over? Plans do include 5" exhaust probably straights, and programmer. What else would I need to look at as I'm looking? I plan on looking until around sep. or oct. unless something exceptional comes along.