Description:

Made from an AA 502 Series Casting, It is set up to build the performance Head of your needs. It Comes with Seats 42x37.5, Guides, with a 12mm plug hole.

The 502 Series comes with our Stage 2 porting with a modernized combustion chamber for increased head flow & performance. There is 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 502

Valve Size: 42x37.5

Head Bore: 85.5

Plug Size: 12mm  (Replacement NGK Number is D8EA)