Zipper’s Muscle 124 Kit combines Big Bore with Big Stroke! At the bottom, a 4-5/8” stroke crankshaft paired with 4-1/8” cylinders establishes the base for 124” of Big Power. An engine this size needs specialized cylinder heads, Zipper’s ultra-high flow Stage IV CNC porting with highly modified chambers along with oversize, unshrouded valves delivers just that. New stress-relieved cylinders are precision-fit with durable forged pistons supplied with high quality 1-1-3mm rings.  Red Shift 657 cams and dual-piston tensioners, Pro-Taper pushrods, longer head bolts and E-Z Adjust pushrod covers are provided with all the gaskets needed for assembly. Case boring required for 4-1/8” cylinders; Timken® bearing conversion, our blueprinted cam chest oil system upgrade for rock solid stability and durability are highly recommended. Show ‘em your rapidly fading tail light every pass, every time!
This kit uses your factory head cores sent in for modification. An exchange may be possible once your cores are cleaned, inspected and qualified for exchange.


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.

*To ensure you enjoy a premium experience, Please fill out a Build Sheet/Job Order Sheet prior to completing an order on the website.
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Weight 1 lbs

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