Fresh Water Cooling System - Full-System (Cools engine block and exhaust manifold). This kit comes complete with heat exchanger, mounting bracket, thermostat & housing, gaskets, hoses, bolts, and installation instructions. Everything you need to convert a currently functioning raw water cooled engine to a full closed system. The Heat exchanger mounts vertically in front of the starter, directly behind the coil and alternator. Fits all MerCruiser inline 6 cylinder engines 1970 and newer. Note: Although this is a tested, operational product use of this kit may void the exhaust manifold manufacturers warranty.