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

Muscle Head Stage V: Program V2-P8-F12, 2.490″ x 2.020″ valve dia, 104cc chambers. Std Copper intake valve seats, B5 Exhaust valve seats, .025″ Jr Hoops & All 9/16″ Head stud inserts. 2.600″ lifter spread, 12ø Exhaust Flange. (pair)