I just installed an OBX ss header along with a high flow cat. Its noticably louder, and there is more pull. Probably because I installed the two at once. I went with the OBX b/c I can pick it up for $135, and plan on going turbo within the next year or so anyway, so I didn't really care how long it will last. Now to just get my vafc, and cam gear installed and tuned.