{"product_id":"exhaust-manifold-gasket-set-for-mercruiser-gm-153-181-2-5l-3-0l-replaces-27-99777a1-sierra-18-4367","title":"Sierra 18-4367 Exhaust Manifold Gasket Set, Replaces 27-99777A1, for GM 153 \u0026 181 CID I\/O Engines","description":"\u003cp\u003eThe Sierra 18-4367 Exhaust Manifold Gasket Set is a replacement gasket kit for Mercruiser I\/O engines equipped with siamese port cylinder heads. It is engineered to seal the exhaust manifold to the cylinder head, preventing exhaust and water leaks at the joint that can lead to overheating, corrosion, or engine damage if left unaddressed. This gasket set is built to meet or exceed the specifications of the original equipment part it replaces, standing up to the heat cycling, saltwater exposure, and vibration typical of the marine exhaust environment.\u003c\/p\u003e\u003cp\u003eThis set is designed specifically for GM 153 and 181 cubic inch displacement (2.5L and 3.0L) engines rated at 120 and 140 horsepower, with serial numbers 6229718 and up, on applications using siamese port cylinder heads. Installing the correct gasket set for this cylinder head configuration and serial number range is important, since earlier serial numbers or non-siamese port heads use a different gasket design. The Sierra 18-4367 directly replaces OEM part number 27-99777A1, so it installs as a drop-in replacement during exhaust manifold service or when addressing a leaking manifold gasket.\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 18-4367\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor:\u003c\/strong\u003e White\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.27 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 030999563309\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEngine Type:\u003c\/strong\u003e I\/O (Mercruiser)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCylinder Head Type:\u003c\/strong\u003e Siamese Port\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFitment:\u003c\/strong\u003e GM 153 \u0026amp; 181 (2.5L \u0026amp; 3.0L) CID engines, 120 \u0026amp; 140 HP, S\/N 6229718 \u0026amp; Up\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eGM 153 \u0026amp; 181 (2.5L \u0026amp; 3.0L) CID engines\u003c\/li\u003e\n\u003cli\u003e120 \u0026amp; 140 HP\u003c\/li\u003e\n\u003cli\u003eS\/N 6229718 \u0026amp; Up\u003c\/li\u003e\n\u003cli\u003eWith siamese port cylinder heads\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e27-99777A1\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat engines does the Sierra 18-4367 exhaust manifold gasket set fit?\u003c\/strong\u003e This gasket set fits GM 153 and 181 cubic inch displacement (2.5L and 3.0L) engines rated at 120 and 140 horsepower, specifically units with serial number 6229718 and up that use siamese port cylinder heads.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat OEM part number does the 18-4367 replace?\u003c\/strong\u003e It replaces OEM part number 27-99777A1, so it can be installed as a direct substitute during exhaust manifold gasket service.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes this gasket set work with any cylinder head design?\u003c\/strong\u003e No, the 18-4367 is designed specifically for engines with siamese port cylinder heads; it is not intended for other cylinder head configurations.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs a serial number range relevant when ordering this gasket set?\u003c\/strong\u003e Yes, the Sierra 18-4367 is intended for engines with serial number 6229718 and up; engines outside that range may require a different gasket set.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the 18-4367 gasket set weigh?\u003c\/strong\u003e The Sierra 18-4367 Exhaust Manifold Gasket Set weighs 0.27 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat color is the Sierra 18-4367 gasket set?\u003c\/strong\u003e The gasket set is white.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-4367 an OEM part or an aftermarket replacement?\u003c\/strong\u003e It is an aftermarket replacement manufactured by Sierra, engineered to meet or exceed the specifications of the original OEM part 27-99777A1 it replaces.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat horsepower ratings apply to engines using this gasket set?\u003c\/strong\u003e The 18-4367 is designed for engines rated at 120 and 140 horsepower within the GM 153 and 181 CID engine family.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the Sierra 18-4367 come with a warranty?\u003c\/strong\u003e Yes, the Sierra 18-4367 Exhaust Manifold Gasket Set is covered under Sierra's standard customer satisfaction warranty.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is included in the Sierra 18-4367 kit?\u003c\/strong\u003e The kit includes the Sierra 18-4367 Exhaust Manifold Gasket Set components needed to seal the exhaust manifold to the cylinder head on applicable GM 153 \u0026amp; 181 CID engines.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988194275547,"sku":"SIE-18-4367","price":29.6,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-4367_lg__78529.1558129433.500.750.jpg?v=1785188885","url":"https:\/\/www.goodvibesmarina.com\/products\/exhaust-manifold-gasket-set-for-mercruiser-gm-153-181-2-5l-3-0l-replaces-27-99777a1-sierra-18-4367","provider":"Good Vibes Marina","version":"1.0","type":"link"}