2600K stable overclock on stock voltages?

[MyPCRunsMe]

I don't want to tweak voltages as I am a amateur overclocker. So what's a stable overclock at stock voltages?
I have a Hyper 212+ w/ 2 fans (push and pull)
Also, which one should I use to overclock? turbo boost multiplier or the core multiplier?
all replies are appreciated.

 

[klepto12]

I think 4.2 Ghz would be ok on stock voltages. also use core to overclock.

 

[Arris]

I think I got mines to 4.4Ghz with no voltage changes. 4Ghz+ can definitely be done with stock voltage. And I only really got the option to overclock the turbo boost. Can disable it and run the cpu at full speed all the time but didn't see the benefit of that for my PCs use.