The best way to determine where you are as far as payload capacity is to weigh the truck, full fuel, passengers and gear, ready to camp. Deduct that number from your GVWR of the truck which is 7200 lbs. I'd suspect that your truck weight will be around 6200 lbs depending on # of passengers, gears and after-market add ons (tonneau cover, step bars, etc). I'd expect the loaded camper weight to be around 7500 lbs and you'd want a tongue weight of 13% or 975 lbs. Sounds like you'll be maxed out on payload...real truck weights will help eliminate the guesswork.
Nights camped in 2013 - 55, 2014 - 105, 2015 - 63