{"product_id":"head-gasket-for-johnson-evinrude-50-hp-outboard-1971-1975-replaces-omc-320745-sierra-18-2964","title":"Sierra 18-2964 Head Gasket for Johnson\/Evinrude 150 HP (1973-91) and 155 HP Commercial (1984-92) Outboards","description":"\u003cp\u003eThe Sierra 18-2964 is a head gasket built for Johnson\/Evinrude outboard power heads, designed to seal the cylinder head against the engine block and maintain proper compression, coolant flow, and combustion sealing. It fits Johnson\/Evinrude 150 HP outboards from 1973-91 as well as the 155 HP Commercial model from 1984-92. Each package contains one gasket, engineered to meet or exceed the sealing performance of the original equipment part it replaces. Because a head gasket sits at a critical sealing point between the cylinder head and block, using a properly sized replacement like the 18-2964 helps prevent compression loss, coolant leakage, and exhaust blow-by that can follow from a worn or damaged factory gasket. This is a direct-fit replacement part rather than a universal or trimmable gasket, so it is matched to the specific power head applications listed below. Boat owners and marine technicians rebuilding or servicing a Johnson\/Evinrude power head on one of these applications can use the 18-2964 as a like-for-like replacement during a head gasket job.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-2964\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 030999314635\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e Head Gasket\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCategory:\u003c\/strong\u003e Evinrude Outboard Power Head Gaskets\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFitment:\u003c\/strong\u003e Johnson\/Evinrude 150 HP, 1973-91\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFitment:\u003c\/strong\u003e Johnson\/Evinrude 155 HP Commercial, 1984-92\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Cross Reference:\u003c\/strong\u003e 320745, 335360, 766779, GLM 33870, Mallory 9-63829\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.17 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Dimensions:\u003c\/strong\u003e 0.39 x 0.39 x 0.39 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePackage Quantity:\u003c\/strong\u003e 1 gasket per package\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eJohnson\/Evinrude 150 HP, 1973-91\u003c\/li\u003e\n\u003cli\u003eJohnson\/Evinrude 155 HP Commercial, 1984-92\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e320745\u003c\/li\u003e\n\u003cli\u003e335360\u003c\/li\u003e\n\u003cli\u003e766779\u003c\/li\u003e\n\u003cli\u003eGLM 33870\u003c\/li\u003e\n\u003cli\u003eMallory 9-63829\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat engines does the Sierra 18-2964 head gasket fit?\u003c\/strong\u003e The 18-2964 is built for Johnson\/Evinrude outboards, specifically the 150 HP model from 1973-91 and the 155 HP Commercial model from 1984-92.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the 18-2964 a direct OEM replacement?\u003c\/strong\u003e Yes, it is a direct-fit replacement engineered to meet or exceed the sealing performance of the original head gasket it replaces on the applicable Johnson\/Evinrude power heads.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat OEM part numbers does the 18-2964 cross-reference to?\u003c\/strong\u003e It cross-references to OEM numbers 320745, 335360, and 766779, as well as GLM 33870 and Mallory 9-63829.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the 18-2964 head gasket weigh?\u003c\/strong\u003e It weighs 0.17 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat are the dimensions of the Sierra 18-2964?\u003c\/strong\u003e The gasket measures 0.39 x 0.39 x 0.39 inches as packaged.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow many gaskets come in one package of the 18-2964?\u003c\/strong\u003e One head gasket is included per package.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWill the 18-2964 fit any Johnson\/Evinrude outboard regardless of horsepower?\u003c\/strong\u003e No, it is specific to the 150 HP (1973-91) and 155 HP Commercial (1984-92) Johnson\/Evinrude power heads listed for this part number, not a universal fit.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-2964 genuine Sierra or a generic aftermarket gasket?\u003c\/strong\u003e It is a genuine Sierra-branded part, part number 18-2964, made to replace the factory head gasket on the specified Johnson\/Evinrude applications.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan the 18-2964 be used as a Mallory 9-63829 replacement?\u003c\/strong\u003e Yes, the 18-2964 cross-references directly to Mallory 9-63829 along with the other listed OEM numbers.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhen should a head gasket like the 18-2964 be replaced?\u003c\/strong\u003e A head gasket should be replaced any time the cylinder head is removed for service, or if it shows signs of compression loss, coolant leakage, or exhaust blow-by, using a matched part like the 18-2964 for the applicable Johnson\/Evinrude engine.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988135817435,"sku":"SIE-18-2964","price":33.6,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-2964_lg__77872.1558125692.500.750.jpg?v=1785187988","url":"https:\/\/www.goodvibesmarina.com\/products\/head-gasket-for-johnson-evinrude-50-hp-outboard-1971-1975-replaces-omc-320745-sierra-18-2964","provider":"Good Vibes Marina","version":"1.0","type":"link"}