[JayChicago]

My thoughts; others may have a better explanation:

So your thermostats never reached 180 degrees, while the engine got up to 245. What could cause that? Trapped air sitting at the top of the heads against the thermostats so the stats are not sensing the true water temp?

I have read that it is a good idea to drill small hole(s) in the thermostat's flange to let trapped air below the stat pass through the stat. Small holes will let just a minimum amount of water pass, so stats will still function to hold back water until up to temp.