6003-4165 455 Big Block Oldsmobile FX Series -19cc Dish Top Oldsmobile Forged Piston Set 4.165 inch bore Pin Dia.: 0.98" Comp Height: 1.75" Piston Ring Kit Option:Pistons - Pins and Locs Without Rings 388 Chevy LS

388 Chevy LS

365 Gen 5 LT Direct Injection

Obviously custom bore size pistons are non-returnable

85 NOTE: Most FE‑series OEM connecting rods require narrowing at the pin end to achieve proper side clearance within the 2

Approx Comp Ratio: 58cc-15

6003-4165 455 Big Block Oldsmobile FX Series -19cc Dish Top Oldsmobile Forged Piston Set 4.165 inch bore Pin Dia.: 0.98" Comp Height: 1.75" Piston Ring Kit Option:Pistons - Pins and Locs Without Rings 388 Chevy LS463 Big Block Oldsmobile, FX, Comp Height: 1. 75, 19cc Dish Top, PIN: . 98", Full Floating or Press Fit, Ring Groove: 1. 2 1. 2 3MM, Stroke: 4. 250", ROD: 6. 735, Approx Comp Ratio: 72cc 10. 49, 75cc 10. 22, 77cc 10. 04 Effective June 15th 2026, These Oldsmobile ring grooves have been updated to the new specifications of 1. 2 1. 2 3mm. Parts manufactured prior to this date feature ring grooves with dimensions of 1 16 1 16 3 16.