Looks like the OP hasn't checked back in as of late but will throw this out there anyway in case they come back later.
Do realize the chip (1090T) you have will tend to run hot, not alot you can do about that with the nature of the chip being what it is. You have six real cores stuffed under a lid that's the same physical size as the lesser/smaller chips of that socket. This means the contact/surface area of the chip to cooler is the same.
With more cores creating more heat it's not going to cool as well as, for example a Deneb or even a Regor core of that socket. Watercooling will help but can only do so much, again the contact area of the chip to cooler is a limiting factor to what cooling efficiency you get whether you run air or watercooling to it.
As stated above there are many things that will affect what you get, be sure to read the above post carefully and let it sink in because the info above is good and he knows of what he speaks of.
We can suggest using a given voltage for x amount of speed but that's it, there is no guarantee how your chip will respond due to these factors all being in play.
As a general expectation of what your chip may possibly do, 4.0GHz on air is about right under load for most any setup and do realize load temps, not temps seen at idle in the BIOS for example is the basis of how to correctly gauge how the chip is doing. Don't be suprised if for some reason it falls short, work with it based on what the chip can do, not on what you expect of it.
Tweaks should be small and deliberate so if it fails to boot or starts crashing you can easily reset things to make it work again. Unless you have experience OC'ing, rarely will you simply throw an arbitrary voltage value at the chip and have it work with stability so... Do it in slow, tiny, methodical steps because you are trying to figure out what your particular chip will/can do and it's all a process of experimentation anyway just to find out.
Give us your system spec's and we can go from there, without the specs it's much harder to almost impossible to make any suggestions of value to that end.
