Hey guys the other day i picked up a pair of bbk shorti headers from a guy for like 35 bucks, think im gonna get them installed today. I see on the net is says they add 10-15 hp but i know thats usually just a ballpark to sell the item, does anyone know if thats what youll really get or is it going to be a little less. will i notice a difference in performance or sound?? thanks again 
First off, $35 is a steal, I paid $299 at American Muscle. A buddy of mine and I finished installing by bbk shorties on my 07 GT yesterday. I made a test run after the install and noticed a huge increase when I stepped on it. As for how much actual hp you gain, who knows?? I was really impressed with the gains I got. I'm running the bbk shorties with pypes o/r x pipe. The difference in the sound was also impressive. When I installed the x pipe, I got a higher pitched raspy sound. Now with the headers installed, I have more of a racey growl. I am really impressed with the bbk shorties. Hope this answers some of your questions.