Russ wrote:
There is no physical difference in the truck size between a 3/4 ton and a one ton STW, so the smart money is on getting the one ton.
It has slightly stronger springs and a higher GVWR and Payload.
Depending on new/used brands and year models and configurations and gvwr/rawr package the OP is looking at we have certain 3/4 ton trucks out here with more actual in the bed payloads or even GVWR based payloads than certain one ton srw trucks.
Like others have said the 3/4 ton HD will work fine for a 10000 gvwr 5th wheel trailer which certainly don't need a one ton srw...unless he just wants one.