501 Series Performance Heads 44 by 37.5 Valves, Pair

This is a brand new Set of 501 High Performance Cylinder Heads for a VW Type 1 2 or 3 Dual Port. Heads comes with Stainless Steel 44mm Intake and a Stainless Steel 37.5mm Exhaust Valves, with Harden Keepers, Chromoly retainers, and Single high rev springs. They are ready to install.   The 501 Series Castings come STD with: Increased material at the intake surface giving you the ability to make much bigger ports . 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.    Engine: VW Type 1 2 and 3 1600 Dual Port Springs: Single or Dual High rev Valves: 44mm Intake by 37.5mm Exhaust Casting: AA Performance 501 Plug Size: 12mm  (Replacement NGK Number i