PCV valve 8M2017060 is for V-8 MerCruiser engines made by General Motors (305, 350, 377 and 454 cid) plus the 575 SCi. PCV valve is an important part of the crankcase ventilation system. It helps maintain optimal level of vacuum in the engine crankcase to extract the products of blow-by along with potentially damaging, excess moisture. Check your owner’s manual or service manual for replacement schedule, specific application and installation instructions. The Quicksilver brand is the leader in delivering uncompromising engine oils, parts and accessories to the marine industry for over 65 years. Quicksilver is the premier supplier of Mercury Marine original Equipment replacement engine parts, oils, and accessories, but also works to serve all original Equipment brands in the marine and powersports industries. It has earned a loyal following by providing the highest quality products that are tested through some of the most rigorous environments and testing procedures. No aftermarket company comes close to the level of research and design as Quicksilver; buying Quicksilver is buying performance, protection and peace of mind.