Fighting with engine temp

I wouldn't advise running cooler thermostats to address a cooling issue. Unless the gauge is the problem, you probably have a scaled up radiator. Doesn't explain why the engine "seems cool," though.

The engine is designed to run at around 190 for optimal performance. A little hotter is better than cooler, up to a certain point. This helps combustion and lubrication efficiency as well as burning off contaminants in the oil.

Post back after you get a good temp gauge on it...