I’ve must have changed out the thermostat at least a half dozen times trying different configurations of 160, 180 and 195 temperature T-Stats. The last configuration and the current one installed is a 160F thermostat with three 1/8″ holes drilled into the flange to allow air to pass through (burping the system of air).

During the last change out one of the threads in the intake manifold gave out. I had to drill an oversize hole and add a Helicoil inside. This also made it more robust. I also changed out the bolts with new ones I got from NAPA Auto Stores.