Replacement forged piston set for 4" bore Super Sidewinder Evolution type S&S engines (excl. TC). Pistons include wrist pins; wrist pin clips and piston rings. Note: In any and all applications the technician must be able to judge components for their suitability in combination with the other engine components; prior to installation. It is of importance that a knowledgeable mechanic will install & make adjustments as required. The rider must follow standard break-in and riding procedures for overhauled engines.