481-X Stage IV Billet Cylinder Heads with Water jackets, Big Port Program #09, 2.450″ x 1.920″ Valve dia. 50ø Valve seats, Jr Hoops @ .017″/.018″ out, 9/16″ Top Row Head Studs. (pair)

Muscle Head Stage V: Program V3-P3-F12, 2.400″ x 1.900″ Valve dia, 102cc chambers. Std Copper intake valve seats, B5 Exhaust valve seats, .025″ Jr Hoops, 5/8″ Top Row & 9/16″ Bottom Row Head stud inserts. 2.600″ lifter spread, 12ø Exhaust Flange. (pr)