Arlid; Had the same situation with old Perkins on last boat. The temperature sender is located in the end of the head where the cooled water enters and the Thermostat is at the opposite end(this is some distance). The water heats up from 160ish where it enters, to the thermostat opening temperature as it travels down the head. Maybe not the best situation but what the heck. I could put my hand on the block pretty much anywhere during moderaate running. Bill Ahrens W. A. Ahrens & Associates 2441 Lloyd Bush Drive Tucson, Arizona 85745 520-991-7650 billahrens@comcast.net