[jhv48]

My new engine reacted exactly as yours is doing. Temp would go right to 212 and sit there. No fluctuation as the 180 degree thermostat was opening and closing. I used a temp gun to check water temps at various points and they all came back normal, but the temp gauge still read 212 degrees.
Jacked up the front end of the car, installed the Lisle funnel in the radiator inlet and ran the engine till the thermostat opened. Saw a few air bubbles in the funnel. This was my fourth attempt at burping the engine. Continued to run the engine till they stopped and then shut her down and sealed it up when it cooled down. These engines are a bear to burp. Keep trying. It's always the simple things that screw you up.
Now my water temp rarely gets over 180 degrees while driving.