Genuine Mercruiser 991551 160F Thermostat
Thermostat 991551 is for 1998 and newer Mercruiser marinised V6 and V8 engines made by General Motors using closed cooling systems and requiring the use of the 160F degree thermostat.
Replaces - 18-3555, 13040, 9-43001, 9-43016 and 99155A1
