Re: Towing new TT question
If the trailer weighs 8400 'empty' then it will probably weigh 9500 or more 'loaded for travel'. You need to find out what the maximum towing capacity of your truck is (manual or dealer), and then subtract the weight of everything you have added to, or carry in, the truck (including passengers, and any amount you weigh over 150 pounds). If you had a diesel engine, you would probably be ok (I think I've seen that truck rated around 12000 pounds with diesel), but I think you'll find that with that smaller gas engine you will be overloaded (I'm thinking the rating may be around 9000 pounds).
I have the 2001 GMC version of that truck, and I had problems (power, not stability) towing 7000 pounds. Probably either GMC improved it or mine has problems, because people with later models of the same vehicle don't seem to have that problem.