WW has worked for me, seems good for a few degrees of temp.
Reducing the amount of coolant/antifreeze from 50% to about 25-30% and a cooler thermostat brought my 454 Dually from 200-205 to 180.
That also made it take longer to warm up, but I can live with that.
On your car, I'd want to run a mech gauge for a test rather than assume the factory gauge is accurate.
More info needed as already asked, but fan/pump speed (smaller pulley) is another solution.
My 438" Street Hemi (+.055 bore) - pretty big cam, 4.10s 4-speed - never saw over 180 no matter what. Added row in radiator, otherwise OEM cooling.