This 4-3/8" stroke 8-1/2" diameter flywheel assembly replaces the original flywheels 2007-'16 HD® big twin engines, when using stock pistons. Wrist pin end of connecting rods is tapered like stock rods. Sprocket shaft does not have the stock style bearing race pressed on. This flywheel assembly is for crankcases with a Timken® sprocket shaft bearing.