Thermostat Housing Compact Design low profile. Can be used on Indmar and many other GM Chevrolet V-6 4.3-Liter and V-8 Small Block 5.0 and 5.7-Liter engines that have dual cooling circulating pump and sea water pump. Use on raw water cooling engines only, comes complete upper and lower housings with a 160 thermostat. Water inlet 1-1/4" and (2) water outlets 1" and Standard size Circulating pump hose outlet.