The JBA shorties are also one of the few headers designed for the new rectangular exhaust ports.
Keep in mind that the stock exhaust logs are good for well over 500RWHP. There are even a couple Cobra's out there making in excess of 600RWHP on a fully stock exhaust system! Headers on this car are not really the best bang for the buck and I'm betting that Mr. 04_snake will agree that they aren't the easiest thing to install either!
U.M.