Is the i5 2500K stock cooler enough for a modest overclock (3.5-4GHz)?

[rockycrrab]

Title says it all!

 

[Frizzo]

the stock cooler isn't even enough for an UNDERCLOCK

 

[Sunius]

It is enough for mild overclock. I was able to reach stable 4.0 GHz with stock cooler. Temps < 70C