I think we understand the law of averages that the auto manufacturers needed an AVERAGE temp T stat for cars shipped all over the world. 180 seemed to be the number-......."
Well, 180 was NOT the number that the Ford engineers were thinking of in 1966 across the entire V-8 range of engines, small blocks, and the big blocks that were going into the full size Fords too. They wanted the operating temperature to be 190 minimum, and 200 - 212 was optimum.
Am still looking for my '67/'68 shop manual, so can't say for sure, . But I do know for certain that '65/'66/'67 HiPo and the & C code 289's, as well as the big block engines going in the full size cars in 1966, did not come from the factory with a 180 degree thermostat. They came with 190 / 192 thermostats. Those don't even fully oven until the engine is 210 - 212 degrees F.
I'm always amazed at the number of people who think 210 - 212 degrees is overheating.....
Z