Mercury 27-879150138 Water Pump Gasket Sierra 18-0327 Aftermarket Mercury 27-879150138 Water Pump Gasket Sierra 18-0327 Fits GM 4 cyl and in-line 6 cyl. Interchangeable with the following: Mercruiser Stern Drive: 27-33956 27-810848 27-879150138 FI5000200 FI5000219 MSRP: Was: Now: $4.73 Add to Cart