Car getting real hot....

lots of confusion here but i think AC or trailer towing water pumps were driven faster to increase fan speed to move more air.To compensate the AC and Trailer towing water pumps had fewer vanes at 6 and smaller at 3 1/2".Standard water pump had 8 vanes at 4 3/8". Both pumps moved the same amount of coolant.
Probably not a good idea to run without a stat or drill holes in it....or change the fluid speed.Temps at 160 are too cool and will increase engine wear. By '69 195 degree thermostats were stock to reduce emissions and burn more efficiently.
I think slant sixes ran a 200 degree thermostat.