Hmm, the CNPS7500 isn't the best aftermarket cooler, but it should definitely get you to 3.0ghz.
I'm not too familiar with your motherboard...but they are mostly the same. Go into the bios and change the fsb to 333mhz, vcore to 1.35, and if you can unlink your ram do that, otherwise make sure it's running around 800mhz