depends on your temps. you may make it stable by increasing voltage, but you will increase temps, so yes a new cooler will allow you to use higher voltage without getting too high temps, which may make it more stable, which may allow you to increase your OC. HOWEVER read the oc guides for core 2 duo, they have a problem whereby between two FSB frequencies they are unstable but above they can be stable, it's called the wall, and you may find that an fsb of 380 is unstable but 400+ is stable. A guy on here called wuzy was very knowledgeable along with others, he's not around anymore, but his articles should be.