New to Rving.....Need Assistance !! F150 Question.

The only thing that keeps my rig viable when towing hills is the 4.10 rear. The four speed limits this setup pretty severely. My tow rating is 9300 lb and I usually leave home around 8K +/- 200 lb. I'm over my 15,300 lb combined pretty often. If you're not in a hurry, you'll make out a lot better. Steep, short entrance ramps onto highways are the main enemy, and the tach needle spends quite a bit of time between 3600-4500. If you have a 3.55, you better have a 6 spd trans to go with it, IMHO.