[Sharps40]

Prolly as simple as a bit of sticky in the new stat or an air bubble in the system....burped and then dropped to cruising temp. 210 is not too hot for a pressurized system in good condition/properly mixed in any event. Run it around a bit, get some highway time to make sure the air is burped out of it and the stat is cycling. Its prolly gonna be like all engines and might read a bit hotter than the stat rateing due to:

actual temp at the sender location, hard running, outside air temps, water pump condition, etc.

Sounds like yer up for some validation driving and a few tweeks then down to some serious cruizing.

My vote is for the air bubble. Only way to get rid of em is to burp, either by a t fittin in the heater hose at the highest point or my way....some highway time!