Diamond Power Intake & Exhaust Valves works with GMC 5.7L 6.0L OHV 2 Year Warranty (This product must be installed by a certified professional mechanic) Same day shipping when purchased before 3pm EST Our products are tested and meet or exceed OEM performance requirements Fits 98-02 Chevrolet Camaro Z28/SS Pontiac Firebird 346 5.7L OHV V8 LS-1 LS-6 Engine Valves are made with excellent quality materials (Nickel, Chrome and Tungsten)