[dwcsr]

First off 210 is not over heating, 210 is not over heating, 210 is not over heating. Your system is doing as it should. Cap off at 210 water will come out of the radiator, shut it off and it will gyser out. Its from the water sucking the heat from the cylinders and heads and boiling out. This is normal on an open system. The system will burp itself once you have enough coolant in it.

With the cap on and the over flow bottle that holds about a half gallon at about 1/3 full cold you should see water at a higher level when its hot. A 180 stat will not make a 210 motor cooler that a 195 stat. The purpose of a stat is to keep a consistant "minimum" temp not a maximum temp.

What psi is the cap?
What pulleys are you running, Undersized?
1950 cfm is not enough to cool a 468. You need to get up to 4500 -5000.
If you have room try a Mark VIII fan 18" 3500 cfm or so.

This is what I did to mine. 4 1500 CFM fans. It will idle in 100 degrees and stay at 200F.