@Ralph058 Where are you getting the load of these trucks? Do you mean the payload (that is, the amount of weight the truck can carry)? That amount is not coded in the number in the model name of the truck. Depending on configuration, a 2021 F350 may have a payload as low as 2,890 pounds or as high as 7,850 pounds.
This is not an unusual year. It's normal for pickup payload to vary by configuration in multiple ways (different GVWR and different curb weight).
@equiraptor Originally, they carrying capacity for the Ford trucks was 1000 pounds for an F-100, 1500 pounds for an F-150, etc.
Similarly there were numbers for Chevy and Dodge.