The exact same assembly used in S&S SH80 Alternator engines Can be used to overhaul an S&S engine or to build a custom engine using similar crankcases and pistons Features 4-1/4" stroke, 8-1/2" diameter flywheels, and 7.440" connecting rods Made in the U.S.A.. FLYWHEEL 4-1/4" 70-84BT