{"product_id":"sierra-18-1977-1-thermostat-housing-for-mercruiser-i-o-replaces-oem-47441-47441a1-fits-gm-260-225-228-898-198-cooling-systems","title":"Sierra 18-1977-1 Thermostat Housing for Mercruiser 305 cid V-8 (1977-1982), Replaces 4765100, 6218461","description":"\u003cp\u003eThe Sierra 18-1977-1 is a marine thermostat housing built to replace the factory housing on Mercruiser 305 cid V-8 sterndrive engines produced in 1977-1982. It is sand cast and machined to exact specifications, then primed and painted to withstand the harsh marine environment, and is finished in white with a polished surface. The housing mounts to the engine block and holds the thermostat in place while sealing the cooling passages, so a worn, cracked, or corroded original housing is a common reason for coolant leaks, overheating, or an improperly seating thermostat. Installing the 18-1977-1 restores a proper seal at this connection point and returns the cooling system to factory-correct operation.\u003c\/p\u003e\u003cp\u003eThis housing is a direct cross-reference for GM\/Mercruiser OEM housing numbers 4765100 and 6218461, so it fits in place of those original parts on the applicable 305 cid V-8 engines without modification. It ships as a single housing unit and is intended as a like-for-like replacement, not an upgrade kit, so existing thermostats, gaskets, and hardware from the original installation can be reused if they are still in serviceable condition.\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 18-1977-1\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e Thermostat Housing\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEngine Fitment:\u003c\/strong\u003e Mercruiser 305 cid V-8\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eModel Years:\u003c\/strong\u003e 1977-1982\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Cross-Reference:\u003c\/strong\u003e 4765100, 6218461\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 1.51 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePackage Dimensions:\u003c\/strong\u003e 17.6 H x 8.7 L x 12.3 W (centimetres)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e Metal, sand cast and machined\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFinish:\u003c\/strong\u003e Polished\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor:\u003c\/strong\u003e White\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCountry of Origin:\u003c\/strong\u003e China\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 808282198206\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\u003cli\u003eMercruiser 305 cid V-8 engines, 1977-1982\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e4765100\u003c\/li\u003e\n\u003cli\u003e6218461\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat engines does the Sierra 18-1977-1 thermostat housing fit?\u003c\/strong\u003e The Sierra 18-1977-1 fits Mercruiser 305 cid V-8 engines built in 1977-1982.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 18-1977-1 replace OEM part number 4765100?\u003c\/strong\u003e Yes, the Sierra 18-1977-1 is a direct cross-reference for OEM housing number 4765100 on the applicable 305 cid V-8 Mercruiser engines.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 18-1977-1 also replace OEM part number 6218461?\u003c\/strong\u003e Yes, 6218461 is the other OEM number the Sierra 18-1977-1 housing replaces on 1977-1982 305 cid V-8 engines.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the 18-1977-1 housing made of?\u003c\/strong\u003e It is a metal housing that is sand cast and machined to exact specifications, then primed and painted, with a polished white finish for long life in a marine environment.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the Sierra 18-1977-1 thermostat housing weigh?\u003c\/strong\u003e It weighs 1.51 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat are the package dimensions of the 18-1977-1?\u003c\/strong\u003e The packaged housing measures 17.6 H x 8.7 L x 12.3 W in centimetres.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 18-1977-1 include the thermostat and gasket?\u003c\/strong\u003e The 18-1977-1 is the thermostat housing itself; it ships as a single housing unit.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-1977-1 a genuine Sierra part or aftermarket generic?\u003c\/strong\u003e The 18-1977-1 is manufactured by Sierra, a marine parts brand, and is sold under Sierra's own part number as its housing for this application.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhy would I need to replace my thermostat housing?\u003c\/strong\u003e A cracked, corroded, or leaking original housing on a 305 cid V-8 Mercruiser engine is a common cause of coolant leaks and overheating, and the Sierra 18-1977-1 is built to restore a proper seal in place of the worn factory unit.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhere is the Sierra 18-1977-1 manufactured?\u003c\/strong\u003e The country of origin for the 18-1977-1 housing is China.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat color and finish does the 18-1977-1 come in?\u003c\/strong\u003e The 18-1977-1 housing has a white color with a polished finish.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan I reuse my old thermostat and hardware with the 18-1977-1?\u003c\/strong\u003e Since the 18-1977-1 is a like-for-like replacement housing, an existing thermostat, gasket, and hardware can be reused as long as they are still in serviceable condition.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988089581787,"sku":"SIE-18-1977-1","price":65.17,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/18-1977-1__20869.1722361156.500.750.jpg?v=1785188626","url":"https:\/\/www.goodvibesmarina.com\/products\/sierra-18-1977-1-thermostat-housing-for-mercruiser-i-o-replaces-oem-47441-47441a1-fits-gm-260-225-228-898-198-cooling-systems","provider":"Good Vibes Marina","version":"1.0","type":"link"}