Assuming you have a 1500 burb. It simply doesn't have enough axle/P tire and wheel capacity to carry a 8500 lb trailer hitch weight and the rest of the stuff you will be carrying. If the 8500 lb figure is a dry weight then your going to have a 10k lb trailer after loading.
Ford markets the F150 with gvwr up to 8200HD gvwr on older trucks and 7850HD GVWR on the newer models. Both can have a 4800 rawr with load E tires and wheels. These trucks can have 10-11k lb tow ratings and 2400-2500 lb payloads in the bed.
Ford also markets a F150 max tow package with a 7600 GVWR and 4550 rawr and around 2000 lbs in the bed.
And the one weight police talk about or use as one to justify their point is the small F150 6600-6800 GVWR and small 3800 rawr with 1300-1500 lb payloads in the bed.
So yes a Ford F150 can pull a 8500-10k lb trailer....if the right package is used.