Perfectly normal. That's a huge chunk of hot cast iron right under the temp sensor, with coolant not circulating. Of course the temperature at the sensor is going to respond to the stagnant coolant. If it's not puking coolant out of the overflow tube you don't have a problem. If it is, just install a recovery tank and you still don't have a problem. Some folks probably lie awake at night wondering why the kitchen faucets aren't dripping!

What temp does it run out on the road? If it's running 180-190 with a 160 thermostat at highway speed, you don't have enough radiator.
Jerry


"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!