when you do go to overclock, 3 GHz is the "easiest" to hit because of the 6850, same chip, same multiplier, different bus. Just raise the bus up to 333 from 266, and up the voltage to ~1.25-1.3. Have your memory run however you want it, minimum DDR-2 667. Leaving it on auto most every board will take care of the voltage and it will work fine. 333x9= 3 GHz.
Being a stock intel board, you may need a little more luck than anything.