481-X Stage IV Billet Cylinder Heads, Small Port Program #10. 2.400″ x 55ø Intake valves x 1.920″ x 50ø Exhaust valves. Jr Hoops @ .017″/.018″ out, 1/2″ dia Head Studs. (pair)

Muscle Head Stage V: Program V3-P2-F12, 2.450″ x 1.900″. 102cc chambers. Std Copper intake valve seats, B5 Exhaust valve seats, .025″ Hoops, 5/8″ & 9/16″ HS inserts. 2.600″ lifter spread, 12ø Exhaust Flange. (pair)