Tire Inflation Specs 2004-2007 Silverado 3500HD

Go with Woodhog's answer. The inflation specs on the tire are a lot more relevant than what the truck mfg has. I say that, because you could put some light weight tire on the truck like a C rated tire might not even hold 65 psi so therefore what the truck specs say to air the tire to aren't appropriate. Whereas the tire mfg will give you the inflation pressure you should put in their tire. My E tires (Perrlli/summer and Cooper/winter) both require 80psi when they have a full load on them.

Bill