Description

Sierra’s 18-3668D Thermostat Kit is designed for use with 1983 and newer GM V-6 and V-8 engines equipped with standard cooling systems, providing a complete solution for dependable engine temperature regulation. It features a 142°F temperature rating and includes the 18-3551 thermostat along with multiple gaskets and sealing components, including the 18-2552 thermostat cover gasket, 18-2553 thermostat gasket, 18-2554 thermostat cover gasket, 18-2917 thermostat housing gasket, and 18-7173 O-ring. These components work together to support proper sealing and consistent cooling system performance under marine operating conditions. Each Sierra product meets or exceeds the original equipment specifications it replaces, ensuring reliable fit and function.

Features

Includes 18-3551 thermostat with a 142°F temperature rating for consistent engine temperature control
Designed for 1983 and newer GM V-6 and V-8 engines with standard cooling systems
Comes with multiple gaskets and sealing components for a complete installation solution
Supports proper sealing and reliable cooling system performance in marine applications
Meets or exceeds original equipment specifications for dependable replacement quality
In Display Pack
Premium quality for longer life
Meets or exceeds manufacturer specs
Backed by Sierra’s limited lifetime warranty