128" | 124" Bolt-On Big Bore Kits / M8 Motors

No Shipping to CA 128 KIT FOR 17-22 M-EIGHT 114/117 4 1/4 BORE; 4 1/2 STROKE;  11.3:1cr (WITH 88cc HEADS) 124 KIT FOR 17-22 M-EIGHT 107 4 1/4 BORE; 4 3/8 STROKE; 11.2:1cr (WITH 88cc HEADS) Aerospace-grade all-aluminum cylinder with nickel-silicon-carbide (NSC) electroplated bore No sleeving allows for larger bore sizes NSC-plated cylinders have less friction for increased horsepower, lower engine temperatures and a longer lifespan True bolt-on kit that delivers major power durability and strength Includes pair of all-aluminum NSC-coated bore cylinders, custom-forged pistons with high-tension rings specifically designed for NSC cylinders and a head/base gasket set Replacement gasket sets available separately Upgraded cylinders studs and head bolts recommended Made in the USA