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Vehicle Info NeededRear Main Seal Gasket, 2-Piece for 1968-1989 Chevy Small Block Gen I Marine Engine 305 ci and 350 ci Reverse-Rotation V8
Ships on 09/15/2026
Lowest Price GuaranteeFel-Pro 17720 is a rear main seal gasket for GM and Chevy Small Block Gen I marine V8 engines using a 2-piece rear main seal and reverse-rotation, right-hand crankshaft setup. Built for 5.0-liter 305ci and 5.7-liter 350ci marine applications, it helps correct crankshaft oil leaks with an application-specific seal made for repair work where accurate fit matters.
Fel-Pro 17720 Compatibility Notes:
- Application-specific design supports GM 2-piece rear main seal configurations used on reverse-rotation, right-hand Chevy marine small-block engines.
- Fits 5.0-liter 305ci and 5.7-liter 350ci marine V8 applications, with coverage also noted for 283-350 CID Chevy Small Block Gen I marine engines.
- Engineered for service replacement use and validated for fit, form, and function in the intended marine crankshaft sealing location.
- Cross-reference information lists Mercruiser 26-35313, OMC 981605 and 983253, and Crusader 33209 and 33376 for buyers matching existing marine part numbers.
Use only on reverse-rotation, right-hand marine engines with a 2-piece rear main seal. This is not for standard automotive rotation engines unless the application data specifically calls for the same seal.
Unsurpassed Quality You Can Trust
Fel-Pro has a variety of specialized rear main seals to cover the unique needs of professional engine builders. Designed and constructed to handle high vacuum, elevated temperatures, and high RPM levels Fel-Pro has you covered. Using only the highest quality materials Fel-Pro rear main seals will keep you leak-free.
