Does anybody have any experience/recommendations of headers for an '09 5.3? Likes/dislikes? Also, is it true that you may experience performance loss due to programming?

 

No experience, but I also just bought an 09 5.3 and before you do anything, check with your local dealer about voiding your warranty, mine will let me do a cat back exhaust if they install without voiding, I also wanted to to a leveling kit but they had something to say about that too

 

yeah check with your dealer first many people go with gibson but i tried the dynatech supermaxx headers with the hi-flow cats and i have a cat back borla exhaust. the performance from the exhaust system is incredible. but its up to you on how much you wanna spend.