90" Monster Big Bore Kits / Sportster

No Shipping to CA Fits '91 - '20 Sportsters 90" KITS FOR 91-20 XL 3 7/8 BORE; 3 13/16 STROKE; 10.5:1cr FLAT-TOPPISTONS (WITH 62cc HEADS) (XR1200 REQUIRES PURCHASE OFGASKET KIT PART #09343181) 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 Monster big bore kits will require case boring 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