A 1/2 ton would have a 4.11:1 rear end and a 1-ton would have a 5.14:1 rear end.

If 55 mph is the highest practical speed for a 1/2 ton, then about 45 mph would be the highest practical speed for a 1-ton.

Maybe someone with a 5.14:1 rear end will post an opinion?

http://chevy.oldcarmanualproject.com/chevyresto/4879.htm