I'm in the same boat- just purchased a 2011 F150 with factory tow package and 5.0l engine. Doing my research to see if I can haul a 28ft 5th wheel which we bought, originally with no plans to tow it. (GVWR 8240 lb). My door pillar sticker puts payload at a little over 1600 lb, and that does not have to include fuel in the tank. It does, however include everything over and above that- dvr, pax, cooler, beer, and the dog. In my case the decision factor is the weight of the 5th wheel hitch itself. If it weren't so heavy, I'd be just barely ok. So I need a lighter trailer. Oh, well so be it. All the best- and don't play around with safety, you'll drive with a much lighter mental load.