I traded in a 2012 Silverado 1500 (and took a real beating)on a 2500HD this past April and am really glad that I did. While the 1500 towed my 7,000 pound trailer okay, the stability and control of the 2500HD is much better. An 8,000 pound trailer will most likely result in you being over your payload, which I don't like to do.
(If you decide to try it, I have a set of Timbrens, Discount Tire has some LT tires, plenty of overload springs are available, and there are fancy hitches that promise to make any pickup into a towing beast. Get out your checkbook, but you will still probably be disappointed.)