129" Big Bore Cylinder Kits / '17-'23 107" M8 Motors

No Shipping to CA Elevate your Harley's performance to monumental heights with the S&S Cycles 129” Big Bore Kit, the ultimate upgrade for M-Eight 107” engines. Designed for seamless integration, this bolt-on kit is the pinnacle of engine enhancement, offering the largest cylinder bore achievable without the need for crankcase machining. Key Features: Maximized Performance: Achieve a 4.320” bore and 4.375” stroke without altering the crankcase. High-Quality Components: Comes with 11:1 forged pistons, ensuring unmatched durability and power. Effortless Installation: All necessary MLS (multi-layered steel) head gaskets and hardware included. Original engine serial numbers are retained, and the stock engine height remains unchanged. Exclusive Cam Cover Badge: Each kit includes a cam cover badge, adding a mark of distinction to your ride. Proudly Made in the U.S.A.: Experience the excellence of American engineering. Elevate Your Ride without Compromise The S&S Cycles 129â€