The Mustang GT (PN 17242) and the Shelby GT500 (PN 17243) long tubes are lightweight and durable stainless steel units including thick stainless warp proof flanges and full merge collectors. The BORLA long tube 1¾” headers are featured on all the Ford Racing backed Miller Cup Mustang Series race cars. These headers are for competition use only and are designed to be used with vehicles equipped with extensive performance upgrades. This is a race header and not recommended for emission controlled vehicles. Contact Borla at (877) 462-6752 www.borla.com