This 4-1/2" stroke 8-1/2" diameter flywheel assembly replaces the original flywheels in S&S 93" KN93 engines with Altenator/Generator style crankcases for custom applications using 1970-'99 style chassis. 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.