***LIMITED ITEM PLS ALLOW 4 BUSINESS DAYS HANDLING TO SHIP*** Piston set 3-7/16 inch bore .040 over size with compression ratio of 7.5:1. Set includes Hasting 3 piece rings 2 wrist pins and 4 circlips. Pistons have a steel expansion control strut. **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,