58-7/8" to the top of the tailgate with the truck in my signature unhitched and unloaded. Yes, the newer trucks are tall. I agree with the others - 6" minimum truck to trailer overhang clearance with 8" preferred. 20 years ago I wrote the check to repair the bedrails on our first truck and 5th wheel to learn this lesson.
Rusty
2014.5 DRV Mobile Suites 38RSSA #6972
2016 Ram 3500 Dually Longhorn Crew Cab Long Bed, 4x4, 385/900 Cummins, Aisin AS69RC, 4.10, 39K+ GCWR, 30K+ trailer tow rating, 14K GVWR
B&W RVK3600