The TTI headers will cost you 20 or more horse power. But they fit better. The Hookers or the Headmans make more power but are a pain in the butt to install. I had to get a local guy at a muffler shop to modify my Headmans. I went from 1 and 5/8 street headers to 2" Hooker headers and the car sounded better and picked up almost. .010 in the 1/8 mile.