An S&S 96" 3-5/8" Sidewinder big bore stroker kit is an economical route to a larger displacement engine. This kit contains nearly everything needed to take a stock 80" Harley-Davidson Evolution big twin engine up to 96" displacement. This kit includes S&S 3-5/8" bore aluminum Sidewinder cylinders and forged pistons, a 4-5/8" stroke dynamically balanced S&S flywheel assembly, complete with S&S heavy duty connecting rods and mainshafts, head gaskets, base gaskets, exhaust gaskets. Stock cases will need to be bored out to 3 5/8".