The Zipper’s Performance Stage 3.5 heads with Manual Compression Releases have a special high flow port design that is one of the largest we can machine into an O.E castings. Special O.S. 2.00” valves, Step Lock Guides, special valve seat machining, 5/16” dual spring for lift up to .675”. These are maximum output heads and are a good option Vs purchasing CVO castings with the added expense of porting. Combustion chambers are 92 cc.

*Not available for Twin Cooled Models

Weight1 lbs
Dimensions1 × 1 × 1 in
Engine Type