So ford put all this time into figuring out gcwr and gvwr just to throw it out the window? Sure the pickup will pull anything you can put behind it but just because you can doesn't mean you should. The tires the op wants to use will only allow him 5670lbs on the rear axle. My truck with my empty gn puts 5500lbs on the rear axle so that doesn't leave him any room for anything in that trailer. If he ever got into an accident the law would throw the book at him and even if he got rear ended while stopped it would be his fault because he should not have been on the road in the first place since he is overloaded by ford and toyo's ratings.