6300-4080 340 Small Block Mopar FX Series -3cc Flat Top Small Block Mopar Forged Piston Set 4.080 inch bore Pin Dia.: 0.984" Comp Height: 1.802" Piston Series Option:FX-3 2618 Alloy with Lateral Gas Ports - XR .225 Wall Pin Upgrade - Spiro Locs 371 Small Block Ford 289

371 Small Block Ford 289 - 302

511 Mopar Viper/SRT

408 Small Block Ford 400M

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

These Oldsmobile ring grooves have been updated to the new specifications of 1

6300-4080 340 Small Block Mopar FX Series -3cc Flat Top Small Block Mopar Forged Piston Set 4.080 inch bore Pin Dia.: 0.984" Comp Height: 1.802" Piston Series Option:FX-3 2618 Alloy with Lateral Gas Ports - XR .225 Wall Pin Upgrade - Spiro Locs 371 Small Block Ford 289346 Small Block Mopar, FX, Comp Height: 1. 802, 3cc Flat Top , PIN: . 984", Full Floating or Press Fit, Ring Groove: 1. 2 1. 2 3MM, Stroke: 3. 310", ROD: 6. 123, Approx Comp Ratio: 62cc 10. 63, 64cc 10. 38, 72cc 9. 48 Effective June 15th 2026, These Sm These Block Mopar 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.