6100-4150 389 Pontiac Late FX Series -7cc Flat Top Pontiac Late Forged Piston Set 4.150 inch bore Pin Dia.: 0.98" Comp Height: 1.71" Piston Series Option:FX-1 4032 Alloy 36 NOTE: Most FE‑series OEM

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

490 Big Block Oldsmobile

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436 Chevy LS

421 Pontiac Early and Late

6100-4150 389 Pontiac Late FX Series -7cc Flat Top Pontiac Late Forged Piston Set 4.150 inch bore Pin Dia.: 0.98" Comp Height: 1.71" Piston Series Option:FX-1 4032 Alloy 36 NOTE: Most FE‑series OEM406 Pontiac Late , FX, Comp Height: 1. 71, 7cc Flat Top , PIN: . 98", Full Floating or Press Fit, Ring Groove: 1. 2 1. 2 3MM, Stroke: 3. 750", ROD: 6. 625, Approx Comp Ratio: 62cc 11. 68, 87cc 9. 08, 124cc 6. 95 Effective June 15th 2026, These Pontiac 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.