I wasn't aware of anything bigger than a 2 ton in '48 from Chevrolet.. in some areas the 'tonnage' rating on the paperwork has less to do with its actual "rating" as it does the 'tax class' the vehicle is in.
It is my understanding that from the factory, the big trucks came with NO BED OR BOX.. so by that line of reasoning, NO box or bed would be 'original'.
Run the numbers of the tag in the drivers side door jam thru
the Vin Cruncher and that'll tell you if you have a 1, 1.5 or 2 ton truck.
