500 Series Type 1 Head "Bare/Bare"

AA 500 Series Bare Casting, It is set up to build the performance Head of your needs. It Comes bare with a 12mm plug hole, and with out Seats orGuides.Giving you the the ability to build any possiblecombo Street head you want. The 500Series Castings come STD with: Cleanflowingcooling vanes, formaximumcooling through the head, and around the intake ports forincreasedHP and over all cooling. Amodernized Combustionchamber, for increased head flow & performance. AsecondFull Fin, soyoucanFlycutyourheads deeper to achieve almost any desired Head CC volume needed. Blocked off rocker stud bosses, to eliminate the O-ring and stoppossibleoil leaks. Long reach 3/4 Inch SparkPlugs, toreduce the chance of cracking betweenthe Valve seat and Plug. Casting: AA 500 Valve Size: N/A Head Bore: 85.5 Plug Size: 12mm (ReplacementNGK Number is D8EA)