bad idea to run without a stat, 160 is fine but you don't want it regularly cooler than that, and idling "for a good period of time" isn't the way to treat an engine, especially if it doesn't have a stat .... easiest way to check the gauge is borrow a thermometer [from the hospital
] and poke it down in the rad water when the gauge shows the usual operating temp, and on a 235 that will be right about the stat temp
Bill
