ok so i just installed the cold air intake system from k&n although its not the right 1(they gave me the 5.3L V8 kit) i still am very impressed with the sound it now makes it just screams!! i think i gave some old ppl a heart attack when i flew by at 140kph!! the kit says it gives the v8 around 13hp at 5222rpm but this is on the S/C V6 so i dont know what gain it gives but u know u got more than u had B4!! so was it worth the $400??? F^CK YA!!!! I LOVE BOOST!!