I did tune it with a vacuum gauge
It's been running with a 160* stat for 4 years.
The car has A/C if I run a higher stat the car heats up very fast at slow speeds with the A/C on. This gives it a fighting chance.
That factory ran 160* stats in a lot of engines combinations with modern day oils it's not much of a problem.
I dont recommend it for everyone but for this iron head engine it works.
All stock 67 and 68 ran 180 unless using alcohol type coolant. I run a 190 thermo in the Florida summer heat with a stock fan and water pump never an issue. I'm not sure how 160 is going to get proper heat saturation for effective combustion.