[68 P.O.S.]

In all reality 210 isn't that bad, not close to overheating, so not too much to worry about there. I'd still be a little concerned about the temp jump at red lights. Not sure why changing thermostats would change things, unless you got a bum one....which is more and more common these days. What's the condition of the other cooling system components? Where's the temp gauge sending unit plugged in at? Where's the vacuum advance hooked up at? Where's the thermostat for the fans hooked up at? I'd have the fans come on at 170 with a 180 stat. When you refilled the radiator and tried to purge it, did you also fill the engine through the theromstat hole?