FWIW, my 74 AMC Hornet 232 6cyl came new with a 205 degree thermostat from the factory. Back at that time I was working for a company that made OEM thermostats for the big three. A lot of them were specing temps in the the 200-205 range in an effort to squeeze a couple more mpg out of the engines.
We also made temp senders and the idiot light senders did not trip the light until 230-235 degrees.