Raises the height of the GM V-6 & V-8 small block (non-Electronic Control) engines with dry joint exhaust system to prevent water from entering the engine through the exhaust system. Maximum height of 6 inches (152 mm).. 4.7 inches (119 mm) for STANDARD COOLING and dry joint exhaust manifolds.. Fits the following models:. 2004 - 2016 MerCruiser Marine V-6 & V-8 (305, 350 & 377 cubic inch displacement) non-Electronic Control engines (serial number 0W310000 and up). 2002 - 2016 MerCruiser Inboard V-8 (350 & 377 cubic inch displacement) non-Electronic Control engines (serial number 0M390000 and up)