I have a 1959 Century Resorter wood boat with a 272 (or maybe 292) Dearborn Interceptor V8. I cannot get it to run warmer than about 125 degrees F. I would think it should run about 160-180. My thermostats both start opening around 125 degrees. I’m thinking I need new thermostats. The thermostat OD is 40 mm so I’m having one hell of a time finding any. Does anyone have any thought on this subject? Much thanks.