I use Carlisle 7.50R16 tubes with the TR440 stem in 17" tires off of late model GM 3/4 and 1 ton trucks.
17.5 is indeed a totally different animal. I just ordered a gooseneck with 17.5 singles to replace 16" duals. We are real pleased since we changed our fleet to 445x50R22.5 singles. So I decided to try singles on a gooseneck.
