Special high velocity port design with 1.850/ 1.610 valves. Valves and
7mm conical springs. Designed for engines with factory or aftermarket flat top
pistons or dome pistons. The combustion chambers are 78 cc to 82 cc range as

Evolution® CNC headwork is performed on supplied head cores; in-house shop time is 5-10 working days.

International Customers – Import duties are not required when shipping your castings for modification. Special low shipping rates are available for your cores; contact your sales representative for details.

Remove heads from engine, wash off oil and ship to Zipper’s as-is. Improper cleaning methods can actually do more harm than good; we suggest you allow us to properly prepare your heads for modification. Extreme care is taken during our preparation process to preserve component finishes. A small cleaning charge applies to heads sent in for modification.

*To ensure you enjoy a premium experience, Please fill out a Build Sheet/Job Order Sheet prior to completing an order on the website.
Click here for Zipper’s Build Sheet/Job Order Sheet

Not legal for sale or use in California on any pollution controlled motor vehicle.
Not legal for sale or use on any EPA pollution controlled motor vehicle.

Weight 27 lbs
Dimensions 1 × 1 × 1 in
Engine Type