What temp thermostat do you have??? What year is your car??? If it's 84 or early/mid 85, you most likely have the narrower radiator...If you have one of the real late 85's, you might have the wider radiator like what is in the 86/7 GN/TRs but without the engine oil cooler...If it's still the original radiator, then some of the tubes in the core are probably plugged up, so it's probably not going to cool right no matter what you do...If you do have the narrower radiator, I would convert over to the wider one for the extra cooling, but you will need to replace your fan shroud or modify your current one to fit...
On top of all that, I see in your sig that you have a Jasper motor in it...Most Jasper's that I have heard about are bored at least .040 over and some even .060...With the thinner cyl walls, the motor will run hotter than the stock bore motor, so that could also be part of your problem as well...
210* isn't really high enough to worry about, yet...but if you have a 160* T-stat in there, then you most likely have a plugged up radiator...I wouldn't let it get any higher than that, though...With a good cooling system, you shouldn't really go over 190* with the ac on and at the most 180* without the ac...