You also need to be aware that AT tires do not have the same weight ratings as the comparable tire in a HT. I don't know why, but it forced me into HTs because of my pin weight. 1010tires.com has an excellent tech section if you are interested.
As to the rating for the Ford wheel, I'm thinking it has to be somwhere. Maybe the tire has to be broken down. DOT is all over stuff like this for tire worker safety, that's why some bigger stuff requires cages to protect the worker. If pick up trucks are not classified as "passenger vehicles" than Standard 120 would apply. The following is from the DOT site.
Standard No. 120 - Tire Selection and Rims for Motor Vehicles Other Than Passenger Cars - Multipurpose Passenger Vehicles, Trucks, Buses, Trailers, and Motorcycles, to Rims for use on those vehicles, and to Non-Pneumatic Spare Tire Assemblies for use on those vehicles
(Effective 8-1-76)
This standard specifies tire and rim selection requirements and rim marking requirements. Its purpose is to provide safe operational performance by ensuring that vehicles to which it applies are equipped with tires of adequate size and load rating and with rims of appropriate size, type designation, and manufacturer identification.