***LIMITED ITEM PLS ALLOW 4 BUSINESS DAYS HANDLING TO SHIP*** 3-7/16 inch bore piston set has a 7.5:1 compression ratio and is standard size. Piston set includes piston rings set 2 wrist pins and 4 circlips. Pistons have a steel expansion control strut set. **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. Bore size is 3.4380 inch-3.4385 inch inner diameter. FITS HARLEY: 1941-1977 FL, 1971-1977 FX, 1966-1984 FL, 1979-1983 FLT, 1982-1983 FXR,