Yes it is only recommended to coat both sides of that design gasket with Mercruiser type Quicksilver Perfect Seal or equivalent (Permatex Aviation Form-A-Gasket available in auto part stores) .... The opposition of using the sealant would be if the gasket has continuity type rivets that run through the gasket... The sealant could affect the operation of the audio alarm warning horn system and/or the temperature gauge and is then not recommended and goes on dry.
