I don't have the board or the memory for overclocking. I have no voltage control on it, so I'm limited to merely raiding the FSB, so I don't know that I could achieve those kinds of overclocks.
If you can get a Northwood they don't really like voltage adjustments! I got my 2.8 400FSB Northwood to 3.7 perfectly stable with the stock cooler and no voltage increases. Made my emachines flyyy!