yeah Fords 3000-3200 lbs payload on their F150HD is a gvwr based payload and will have to be spread over the F150 fawr/rawr. There is no F150 with enough rear axle to carry 3000 lbs in the bed.
The most a F150HD with the 4800 rawr can carry is in the 2300-2500 lbs range before exceeding its rawr when we run actual scaled numbers.
Now if the F150 had a full length overhead rack then approx 2400 lbs over the rear and the rest (600-800 lbs) over the trucks front axle.
The 2500 GM is the lightest 2500 and with the full floater AAM axle has a 6200 rawr....and can actually carry approx 3000-3400 lbs in the bed ...depending on model selected.
Fords F250 at 6340 rawr ain't no slouch for in the bed real world payloads either.