This 3-5/8" big bore kit could be used to replace the cylinders and pistons of a S&S Cycle SH96 engine or a stock HD Shovelhead engine that has been upgrades with S&S Cycle 96" Hot Set Up Kit. High strength engineering grade grey cast iron Superior wear resistance Durable powder coat finish The kit includes S&S Cycle3-5/8" bore forged pistons with rings and wristpins, head gaskets, base gaskets, exhaust gaskets, and instructions Cylinders are longer than stock, so longer pushrods, and manifold must be used