I have an 06 Silverado Crew Cab 5.3. Mods are K&N CAI, Magna Flow exhaust, Diablo Performance with 93 octane and 305/40/22's. I think i have a 3.23 rear and its a turd off the line. I was wanting to put in a cam in and everything is stock. It is my DD and on the highway i'm getting 21mpg's. I do pull a small trailer occassionally. Would a 265 be the way to go? Any other suggestions would be appreciated. Looking all this up will make you go crazy.