hytech, anr, dtr, edlebrock, hookups, just to mention a few brands that are good. The hytech, anr, dtr, and hookups are all made when ordered, so it takes a little bit to get the header, but its not a machine that makes your header, and the person who makes your header will most likely make 10 whp depending on how modded your motor is. These headers cost anywhere from like 750 up to like 1700.