original poster, for some fun and educational videos, watch TFL (the fast lane truck). They do "tests" by running up the Ike with a trailer loaded to the max weight of the truck. Specifically, watch the vid on the Nissan Frontier pulling a 6100 pound trailer up the hill. Being from Colo, I'm sure you're familiar with the run up to Eisenhower.
That's a 4.0 liter V6 truck.....went right up the hill. Watch that, and then think about how much "more of a truck" your F150 is.
I tow two of my trailers with a Frontier. Every summer I go to Colorado with this travel trailer behind my Frontier, and have no problem at all going up or down the hills.
Again, your F150 has a lot of capability, in spite of what some naysayers might have you believe. Enjoy your new camper and the fun times with your family.