{"product_id":"uanofcn-exhaust-flapper-replacement-for-mercruiser-807166a1-2-pack-with-grommets-metal-rubber-oem-fit-for-175-370-engines","title":"UANOFCN Exhaust Flapper Replacement for MerCruiser 807166A1 2-Pack with Grommets — Metal-Rubber OEM Fit for 175–370 Engines","description":"\u003cp\u003e\u003cstrong\u003eUANOFCN 807166A1 Exhaust Flapper is a direct-fit replacement shutter assembly designed to restore proper exhaust sealing and water shutter function on compatible MerCruiser stern drive 175–370 series engines.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eWhen an exhaust flapper fails it can cause water intrusion, noise, and reduced engine performance. This replacement set from UANOFCN includes two metal-and-rubber flapper shutters plus four grommets and is engineered to match the fit and function of the original MerCruiser 807166A1 \/ GLM 89175 units. The parts are intended for a range of V6 and V8 MerCruiser and GM small- and big-block applications across specific model years and joint types; check fit notes carefully before ordering.\u003c\/p\u003e\n\n\u003ch3\u003eWhich engines and configurations does this flapper fit?\u003c\/h3\u003e\n\u003cp\u003eThis replacement is compatible with many MerCruiser and GM V6\/V8 stern drive models that use a 3\" water shutter and the referenced part number. It covers a variety of model years and both wet- and dry-joint manifolds, but it is not universal.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eFits MerCruiser 807166A1 and GLM 89175 applications with 3\" water shutter.\u003c\/li\u003e\n  \u003cli\u003eCompatible with MerCruiser V6\/V8 w\/4\" Y-pipe (1992–2001) and GM V6\/V8 small-block dry joints (2002–2010) with specified angles.\u003c\/li\u003e\n  \u003cli\u003eSupported engine models include 175–205 V6 (GM 229\/262), 200–320 V8 small-block (GM 305\/350\/377), and 330–370 V8 big-block (GM 454\/502) where original joints are wet.\u003c\/li\u003e\n  \u003cli\u003eNot suitable for V6 one-piece manifold designs or early V8s with through-pinned flappers—use alternate part numbers in those cases.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow durable and OEM-like are these components?\u003c\/h3\u003e\n\u003cp\u003eThe UANOFCN shutters combine metal cores with molded rubber sealing surfaces for a balance of strength and flexibility. Materials and construction aim to meet OEM dimensions and function so the shutter moves and seals like the original component.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eMetal inner structure for structural integrity under exhaust flow.\u003c\/li\u003e\n  \u003cli\u003eRubber sealing edge provides a water-tight shutter against the exhaust outlet.\u003c\/li\u003e\n  \u003cli\u003eIncluded grommets supply proper mounting and vibration isolation.\u003c\/li\u003e\n  \u003cli\u003eManufactured to match OEM fit tolerances for straightforward installation.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat should I know about installation and fit notes?\u003c\/h3\u003e\n\u003cp\u003eInstallation typically involves removing the old flappers and grommets, cleaning the mounting area, then pressing the new units into position with the supplied grommets. Verify the manifold joint type and year range first to avoid misfit.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eRemove exhaust assembly access panels to reach flapper area.\u003c\/li\u003e\n  \u003cli\u003eClean mating surfaces and inspect for corrosion or warped housings before installing.\u003c\/li\u003e\n  \u003cli\u003eUse supplied grommets; confirm that sealing faces align and flap moves freely.\u003c\/li\u003e\n  \u003cli\u003eDo not use this part on V6 engines with one-piece manifolds or early pinned V8 designs.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWho is this for: Boaters and marine technicians who need a cost-effective, OEM-dimension replacement exhaust flapper for MerCruiser and compatible GM stern drive engines. This product suits owners of mid-1990s to 2010 models with the specified joint types who want to restore proper exhaust shutter operation without buying a full manifold assembly. Confirm your engine model, joint angle, and manifold type before purchase to ensure a correct match.\u003c\/p\u003e\n\u003csection class=\"product-faq-snippet\"\u003e\u003ch3\u003eFAQ\u003c\/h3\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Will this flapper fit my MerCruiser V6 with a one-piece manifold?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: No. This 807166A1 flapper will not fit V6 engines that use one-piece manifolds; a different part (807166A2) is required.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Are grommets included and do they match OEM sizes?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes. The kit includes four grommets matched to the shutter mounts and sized for OEM-style installation.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"UANOFCN","offers":[{"title":"Default Title","offer_id":48085964521630,"sku":"B079KBNV5C","price":49.98,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0781\/2041\/9486\/files\/uanofcn-exhaust-flapper-front-view.jpg?v=1785881614","url":"https:\/\/northtrailauto.ca\/products\/uanofcn-exhaust-flapper-replacement-for-mercruiser-807166a1-2-pack-with-grommets-metal-rubber-oem-fit-for-175-370-engines","provider":"North Trail Auto","version":"1.0","type":"link"}