What do you have for a motherboard?
With an unlocked multiplier on a cpu it's fairly easy to overclock and when you reach the point where it's not stable and you have to add voltage then you have to see at what spped the cpu is at and how much further you have to go to get to your target speed and if it'sd worth going further by adding voltage.
If your close enough then you may just call it a day and be happy with what you have without adding voltage.
For your information the 2500k will be fine up to 1.35v and you don't want to go over that as it will shorten the life of the cpu. I know from what your post says that you won't go anywhere near that but it's just so you know.
Any time you can overclock the cpu to a speed that you comfortable with and you don't have to add voltage it's a good thing and won't harm the cpu at all.
wow, thx man, i was gonna upgrade my mobo to z77 and ram to a 1600 soon. (my rig at my signature.)
thx for the info.. i knw abt adding multiplier n stuff, but i just want to be on the safe side and ask abt vcore first.. to be safe..