There is one thing that people have to remember about Ivy Bridge cpu's and that is that they are specificly designed to be a low power alternative to the higher voltage Sandy Bridge. Ivy Bridge 77w TDP and Sandy Bridge 95w TDP what this means is that Sandy Bridge can handle added voltage when overclocking while Ivy Bridge does not handle the added voltage as well. The result is that when overclocking the Ivy Bridge and you are adding voltage there comes a point where the added voltage cannot be handled very well and the cpu releasesd a large amount of heat that has to be dissapated in order to continue with a stable overclock and not damage the cpu. Since every cpu is just a bit different from another that voltage point will be different with each cpu chip.
Right now your at a good place with the voltage and the temps and it won't be much more and you'll hit the heat build up point. There is an article that I have linked that was posted here at Tomshardware that will explain it further and the title is about the 3770k but it does include any Ivy Bridge cpu that is overclocked.
The bottom line is that the Ivy Bridge is not as overclockable as the Dandy Bridge and it would be up to you if you want to continue so I would read the article first so you know more of what to expect and how to deal with it.http://www.tomshardware.com/reviews/ivy-bridge-overclocking-core-i7-3770k,3198.html