Re: Overclocking with stock heatsink
It's perfectly fine to overclock on a stock heatsink. In fact, it is no different than overclocking on an after-market heatsink. Keep your eyes on the temps and push it as far as you can without passing 50C (under full load).
I don't know why, but when someone asks if they can overclock on a stock heatsink, everybody is like, "Oh noes! Don't do it! It's not good for you!". Guys! It doesn't make a difference. It's not like 40C is hotter on a worse heatsink. The whole idea of buying an after-market heatsink is so you can push your OC further.
PS: 50C is my recommendation. You can choose to stay below whatever Intel says is the thermal limit for the processor.