These S&S® Super Stock® cylinder heads for 1991-'03 HD® Sportster models feature a specially shaped combustion chamber and require special pistons that must be purchased separately. (Not compatible with stock style flat topped pistons) Large 2.000" intake and 1.605" exhaust valves and high flowing ports supply plenty of air. Compatible with cams with lifts up to .650". Compatible with stock 3-1/2" or 3-5/8" bore engines. Order appropriate gasket kits separately for your specific bore size. Black wrinkle powder coat finish.