I think that I finally have the temperature stabilized where I want it.
After installing a lower temperature thermostat (I can't remember the opening temperature) and manually turning the electric fan on and off, I have the temp gauge needle in the safe zone. I just need to wire up the temperature switch on the radiator. I'll still keep a manual switch on the dash, but the radiator temperature switch should work just fine.
I still need to modify the cluster for an input button for the electronic speedometer.