GM Small Block Cylinder Head Gasket | Sierra 18-3876 Seals cylinder head to engine block on GM 305 and 350 cu. in. marine engines. For all GM 5.0L 305 CID & 5.7L 350 CID marine engines Sold individually-2 required per engine Replaces Mercury 27-75611, 27-75611001, 27-48330, 27-34278 Replaces Crusader RM0195 Replaces Indmar 551654 Replaces OMC 3853380 Replaces Pleasurecraft Marine RM0195 Replaces Volvo Penta 38533