I got mine to 4Ghz at stock volts and cooler but temps were getting up to 72C (ambient temp was around 20C), could've gone higher but I got a better cooler soon after.
So yes it'd be fine on stock cooler but I wouldn't go too high.
I would reccomend the 212 Evo if you are thinking of buying one of these coolers, especially as in America it is the same price as the Freezer 7. (I am in the UK, the 212 Evo is much more expensive here)
Temperatures are your worst enemy on Ivy Bridge. Temperatures is what will determine your threshold. You could probably manage a small overclock with a stock cooler - but I would personally never ever try it.
I am running a CM 212 EVO I paid around 30$ for and I'm quite happy with it. Don't forget Arctic silver 5 if you do try it.
I am running stable @ 4.4ghz with temperatures averaging high 50C and spiking as high at low-mid 70C during stress test.
My idle temps are high 20's to low 30's
You should check what your temps are at idle currently before you even think about OCing.