Camaro/Firebird 98-2002 LS1 MAC Performance Header System w/Offroad Y-pipe, No Catalytics, shipping is not included. ALLOW 4-6 WEEKS FOR DELIVERY. This True Fit Header System is made from heavy 16ga. tubing, comes complete with a 2.5" aluminized steel & Dura Black coated Y-pipe and 3" Collector, also includes all necessary hardware. LS1 headers are 1-3/4" primaries. All headers have laser cut flanges to ensure proper seal and include our True Fit design to eliminate collector gaskets. Item #MAC-TF4398 98-2000 MAC-TF4420 2001-02