I don't know how good this cooler is but you should be able to overclock it at least some. Just stay, preferably, at least 5 degrees below max temperature for your CPU ( under load of course ).
Things that you should be able to achieve with just a multiplier change:
CPU - 3,6-3,8 Ghz
CPU-NB - 2,2-2,4 maybe 2,6 Ghz
All in all, most of these chips can do about 3,9-4,1 Ghz max with CPU-NB ending around 2,8 Ghz.