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).. 3 inches (76 mm) for STANDARD COOLING and dry joint exhaust manifolds.. Fits 2002-2004 MerCruiser Marine V-6 & V-8 (305, 350 & 377 Cubic Inch Displacement) non-Electronic Control engines (serial number 0M615000-0W309999).