The big 3 have variously marketed their over 8500 gvw trucks as 3/4 and 1 ton, when equipped with single rear wheels. For example, I had a D250 @ 8550 in 1980, and a D350 @ 8510 lb. in 1985. Chevy had the C6P option on the 3/4, and the 1 ton ratings with the same basic suspension, frame, etc. stuff on the truck. Ford did similarly. Our present 8800 gvw single rear wheel BR2500 could be considered a one ton by the above criteria. Marketing.