Stock Head W/ seats and guides 40mm Intake 35.5mm Exhaust
AA 500 Series Casting With seats and guides 40mm Intake 35.5mm Exhaust, It is set up to build the performance Head of your needs.
The 500 Series Castings come STD with: Clean flowing cooling vanes, for maximum cooling through the head, and around the intake ports for increased HP and over all cooling. A modernized Combustion chamber, for increased head flow & performance. A second Full Fin, so you can Fly cut your heads deeper to achieve almost any desired Head CC volume needed. Blocked off rocker stud bosses, to eliminate the O-ring and stop possible oil leaks. Long reach 3/4 Inch Spark Plugs, to reduce the chance of cracking between the Valve seat and Plug.
Casting: AA 500
Valve Size: N/A
Head Bore: 85.5
Plug Size: 12mm (Replacement NGK Number is D8EA)