Sierra 18-3557 ThermostatSierra replacement 143 thermostat for Chrysler/Force/US Marine, Johnson/Evinrude Outboards, Mercrusier Stern Drives, and Volvo Penta engines. Fits MCM GM in-line 6 cylinder; Use with: 18-3669 Thermostat Kit; 18-3669D Thermostat Kit; 18-3626 Thermostat Kit; Interchangeable with: Chrysler/Force/US Marine; F335068; GLM; 13080; Johnson/Evinrude Outboard; 382385; 396987; Mallory; 9-43024; Mercruiser Stern Drive; 47594; Volvo Penta; 21148403;