Yea, I figured that out when I looked at them. I did grab a 195. I boiled them and both didnt open until well after the water started to boil. Which is over 200 degrees. They do still open and close, just my 180 shouldnt take as long as the 195. And there is a little rub mark on the copper piece in the spring. Im guessing my thermostat is sticking?

 

This is purely conjecture since I've never tested it, but it makes total sense in my head. Keep in mind that your cooling system is like a pressure cooker. That pressure would be trying to push the thermostat open, a condition you don't have while it's sitting in the pot on the stove. That would help to explain why the thermostats didn't open at their setting.

 

Im certain Ill have another problem shortly down the road, but I found the problem by doing a little research on my thermostat.
I have the Prestone Gen 2 180 thermostat. I ended up putting that 195 I found in a camaro at the junkyard in since I know it works and its the right size.
Apparently the Gen 2's were recalled because they put some added piece in it which made the thermostat taller. Comparing mine from the junkyard one, its significantly taller. And there isnt much room between the thermostat and the block. They were recalled for hitting the block when they tried to open. So they either didnt open at all, or in my case, opened very partially.