I've run the numbers every which way but Sunday with an F-150, 5.4 V8, and 3.73 axle and my limit across all numbers is 6,500 lbs. And I have a greater cargo capacity probably mostly because the truck is lighter than the Expy.
I will differ on automatically using GVWR of the TT IF you intend to upgrade vehicles in the future AND only if the TT has a high cargo rating. I've looked at TTs with a dry weight around 5,000 but GVWR's around 7,000. I will not two 7,000#'s with this truck but I can throw a 1,000 lbs of gear in the TT and still be at 6,000. That puts me well under my GCWR and tow rating but a little margin on TW and cargo capacity of my truck. Also probably helps my TT that I'm not stressing it to the GVWR either.
