With REDiesel, you will receive High-Quality Parts for you Engine from well established brands. 2 Pc Thermostat is a replacement part for the Series 60 / 50 Detroit Diesel engines. Thermostats are rated for operation at a temperature of 170 Degrees. This part helps regulate the engines temperature and allows the engine to run at optimal performance. This is an OEM-quality part that meets or exceeds OE specifications.