Depends from your Cpu, but if you've a higher temperature you can simply modify the Pep66 installing a second fan like done
it's written in Italian but, if you want, i can help you.
Well a friend of mine used a pep66+ delta 38cfm fan and got his [email protected] If your chip is good it probably will do the job... If the temperatures are still high, do the 2 fans trick... It Kick´s some asses! Pep66 no wrong! Better with silver artic!