I would recommend you install a 180 F thermostat.
Mine has never gone past straight up.
The fans will turn on at about 210 F.
I like to keep mine 2 notches below staight up....or about 175 F....all the time. The only way to do this without replacing the radiator with more rows of fins, is to install a switch to keep the fans on high speed.
When the A/C is on, the low speed fans turn on.
If I turn off the A/C and turn on the low speed fans, it stays about 1 notch below straight up .....or about 185 F.
GM designed the engine to run most efficiently (for emissions) at a high temp of 195 - 220 F.