This 4-1/2" stroke 8-1/2" diameter flywheel assembly replaces the original flywheels in S&S 113" V113 engines. Flywheels are CNC machined from heat-treated, closed die, steel forgings, and are stronger than cast iron or late style steel flywheels. Dynamically balanced and fully assembled with premium quaility S&S mainshafts and heavy duty 7.440" connecting rods. Pinion shaft is 1/4" longer than stock to accomodate the wider S&S Special Application crankcases.