450sl Operating Temp

[UPSTATE NY]

Hello. I have a 76 450SL and I'll be damn if I know what normal operating temperature is. I'm concerned about damaging the engine with it operating to hot.

The car runs at 175 +, put very rarely does the temp gauge hit the mark between 175 and 250. I think this is 212 degrees because this is when the aux. coolant fan comes on.

That said, how hot can this engine run without doing damage ?

Thanks for any input.
JOB