I just noticed your TV under your signature. Unless you're planning to upgrade trucks, you might be better off with a Grand Design. The AFs are VERY heavy- even the shorter ones. Personally, I wouldn't want to tow mine (which, at 12K, is lighter than the later versions) with anything less than a 3500.
The short coming of the early Duramax's is the OEM 245/75R16E tires on narrow OEM rims that limits the rear axle to 6084 pounds. Installing 265/75R16E on the appropriate wider rims, gives 6830 pound capacity on the rear axle. Other than that these when licensed for the weight are very capable tow vehicles.
Thanks I thought I updated it, I guess I didn't click save. We are going to look at a GD on Saturday.