S&S Cycle 3-Piece Flywheel for 124ci. S&S Twin Cam - 4-5/8in. Stroke 320-0475Vast improvement over stock flywheels which shift out of true under heavy load Heat treated 4140 material is 114% stronger than stock, eliminates thrust washer Larger 1. 671in. crankpin, increased cross sectional area for increased crank pin clamping force. No welding required Integral mainshafts, truer flywheels and less vibration Notes: Strokes longer than stock will require S&S piston oiler set #31 2026. 07 up stock rod length is 7. 659in.. Stock