[knomadd]

I'd leave it alone. You said about 94* outside temp, idling (no air flow) and it only got to 210? Modern vehicles operate around 210* all the time. Everything's fine. Except I'd change that 165* t-stat. It's so low that you're not allowing the coolant to sit in the radiator long enough to cool efficiently. When you run a t-stat that's more than about 20* below the operating temp, it will never close and let the coolant in your radiator cool off like it should. If you ran a 185-195* t-stat, it would close when the coolant was below that temp, allowing what's in the radiator to cool more. It doesn't take long to get back up to the t-stat opening temp, but it does help the cooling system run efficiently. It could be as little as a 10 second delay on a hot day, but if it's that warm out, a 165* t-stat wont close.

As for going with an aluminum radiator... it won't help you that much. IIRC, copper actually allows heat to escape faster than aluminum. It's the brass that's used to hold it together that reduces the efficiency of the copper radiator. A good 4 core copper/brass radiator should be very competitive to an aluminum radiator. Also, aluminum radiators are the weak link in electrolysis. If you have a charge in your coolant that erodes the metal (electrolysis), your radiator would be the first thing to go.