Capt Skup wrote:
I have got a hell of a load and those numbers come from the sticker that Ford was nice enough to place in the door sill of the truck. I am not an arm chair mechanical engineer, I will go with what the manufacturers recommends. Been working fine for 5 years that way. I have used those pressure for 32,500lbs GCWR on down for the boats and toys, works just fine.
The reason I ask is the MFG will post psi based on max load the truck is rated for. That may or may not be the case with your load. Up to you, might be worth weighing the axles and compare to weight charts for your tires.