{"product_id":"sierra-18-0664-marine-valve-cover-gasket-replaces-mercury-27-17467-omc-3852687-fits-gm-305-350-5-0l-5-7l","title":"Sierra 18-0664 Valve Cover Gasket, Replaces 909529, Fits GM 305\/350 5.0L \u0026 5.7L Engines","description":"\u003cp\u003eThe Sierra 18-0664 is a valve cover gasket engineered to seal the valve cover against the cylinder head on GM 305\/350 cubic-inch marine engines, including 5.0L and 5.7L applications. It creates the seal that keeps oil inside the valve cover assembly and prevents leaks at the cylinder head mating surface, a common failure point on inboard and sterndrive engines that see extended run time and heat cycling.\u003c\/p\u003e\u003cp\u003eEach 18-0664 is sold as a pack of 2, giving you both gaskets needed for a V8 engine's left and right valve covers in a single purchase. Replacing worn valve cover gaskets is a routine maintenance step during valve cover removal for inspection, tappet adjustment, or general engine service, and using a properly sized replacement gasket helps ensure a leak-free reseal.\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 18-0664\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e Valve Cover Gasket\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePackage Quantity:\u003c\/strong\u003e 2 gaskets per pack\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFits:\u003c\/strong\u003e GM 305\/350, 5.0L \u0026amp; 5.7L engines\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.29 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 808282237189\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eGM 305\/350 cubic-inch engines\u003c\/li\u003e\n\u003cli\u003e5.0L and 5.7L engines\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e909529\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat engines does the Sierra 18-0664 fit?\u003c\/strong\u003e The Sierra 18-0664 valve cover gasket fits GM 305\/350 cubic-inch engines, including 5.0L and 5.7L versions.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs 18-0664 the same gasket as OEM 909529?\u003c\/strong\u003e Yes, the Sierra 18-0664 replaces OEM part number 909529 and is designed as a direct-fit substitute for it.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow many gaskets are included with part 18-0664?\u003c\/strong\u003e Part 18-0664 is packaged as a set of 2 gaskets, enough to cover both valve covers on a V8 engine.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the 18-0664 gasket weigh?\u003c\/strong\u003e The Sierra 18-0664 valve cover gasket has a shipping weight of 0.29 pounds for the 2-gasket pack.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDo I need one or two gaskets for my engine?\u003c\/strong\u003e A V8 engine has two valve covers, so you need two gaskets, which is exactly what comes in one pack of the Sierra 18-0664.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs this a genuine Sierra part?\u003c\/strong\u003e Yes, this gasket is manufactured and sold under the Sierra brand as part number 18-0664.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan I reuse a valve cover gasket after removing the valve cover?\u003c\/strong\u003e Gaskets are generally not reused once removed since they lose their sealing compression; installing a new Sierra 18-0664 gasket at reassembly gives the most reliable seal.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the function of the valve cover gasket on a GM 305\/350 engine?\u003c\/strong\u003e It seals the joint between the valve cover and the cylinder head, part number 18-0664 being the gasket sized for GM 305\/350, 5.0L and 5.7L engines.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 18-0664 come as a full gasket set or just the valve cover gasket?\u003c\/strong\u003e The Sierra 18-0664 is specifically a valve cover gasket, sold two to a pack, and is not a complete engine gasket set.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat OEM number should I cross-reference when ordering 18-0664?\u003c\/strong\u003e Sierra 18-0664 cross-references to OEM part number 909529.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988084404443,"sku":"SIE-18-0664","price":26.56,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0664_lg__88774.1558120740.500.750.jpg?v=1785188797","url":"https:\/\/www.goodvibesmarina.com\/products\/sierra-18-0664-marine-valve-cover-gasket-replaces-mercury-27-17467-omc-3852687-fits-gm-305-350-5-0l-5-7l","provider":"Good Vibes Marina","version":"1.0","type":"link"}