501 Series Performance Heads 42 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 42mm 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: 42mm Intake by 37.5mm Exhaust

Casting: AA Performance 501

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

Bore: 85.5, works with 85.5,87, and 88 slip in kits

Bore: 92, works with 88 thick wall, 90.5 and 92mm kits

Bore: 94, works with 92 thick walls K and M, and 94mm kits

Please Pick Bore size, and Spring Upgrade when ordering Above