Did some work today. I removed the thermostat, drilled two 1/8" holes, and reassembled. I also confirmed that it is a 195 thermostat and that the cap is 16lbs.
I also attempted to move the sending unit into the manifold. The sending unit I pulled out of the head is 3/8" pipe thread, but the holes in the manifold are 1/2". My Dad said to get a sending unit for a car from the 60's or 70's. Can anyone confirm this is correct or that the resistance is the same?