Expedition Tow Vehicle - Doing the Math - Will it work?

Here is what I know: I have been towing my TT for four seasons with at least one 2,000 mile plus trip every year and three or four shorter 200-300 mile trips each season. I have had zero issues with my Expy. In the six years ive had this Expy I put one set of brakes in the rear and one set in the front, also replaced the rear axle seals one time. I have 147,000 miles on it.

Highest elevation towed so far, Clingmans Dome Tennessee @ 6,000+ feet.