never heard the story about a six needing to run warmer than a V8, 180 thermostats were factory issues prior to 1968(which was the year the rest of world introduced to smog controls). In an effort to insure more complete combustion (and therefore less smog) the 195 thermostats were introduced at which point the underhood temps soared. During a trip on a 100 degree day in texas it was unpleasant to touch the dipstick whilse making a pitstop along the interstate. Underhood rubber parts suffered until many years later they changed to more heat resistant compounds, we were re-introduced to vapor lock, low milage valve jobs, and generally poorer drivability which maxed in 1974 (the year prior to cat convertors) every mfg's '74 cars were the MOST DOGGY of all their years. But you sure had a hell of a heater in the winter time, and perhaps less smog.
