HELLO EVERYONE,NEW MEMBER..
I HAVE A 2007 SIERRA CLASSIC CREW CAB.DOES ANYONE KNOWS HOW MUCH MORE HP DO YOU GET IN YOU INSTALL A K&N INTAKE SYSTEM?

 

on my 06 they said +11 but it was at 5000+ rpm at wide open throttle. during normal driving you probably wont feel a difference.
i did gain about .5-1mpg though. (takes awhile to pay off due to the cost of the intake itself)