***LIMITED ITEM PLS ALLOW 4 BUSINESS DAYS HANDLING TO SHIP*** S&S forged piston set 3-7/16 inch bore is standard size. Set includes rings wrist pins and retainers. Machined to fit 4-3/4 inch or 4-5/8 inch stroker flywheels. **Note: Run engine at moderate speeds for at least 500 miles avoiding excessive running in lower gears in order to properly break-in new pistons and rings. FITS HARLEY: 1941-1977 FL, 1971-1977 FX,