Cpu-z showing wrong Clocks no matter what.

How do you have your Turbo Ratio option configured? In your BIOS you have a couple different options for achieving the overclock by changing the Turbo or Core Ratio. If you really want it to stick to one speed and not change based on load (why you would do that is beyond me.....) but here is the way.

In your BIOS;

AI Overclock Tuner = Manual
Turbo Ratio = Manual
Ratio Synchronizing Control = Disabled
1-Core Ratio Limit = x48
2-Core Ratio Limit = x48
3-Core Ratio Limit = x48
4-Core Ratio Limit = x48

Save and exit. With that being said, I'm not sure why anyone wouldn't want dynamic cpu speed and voltage control enabled on modern platforms. In the old days running any power saving or dynamic cpu features when overclocking would result in system instability, failed overclocks etc. But that just isn't true on most hardware now, unless you are trying to achieve very aggressive overclocks. I don't consider 4.8Ghz on a good 2700K an aggressive overclock.

If I were you I'd be trying to use offset voltage and keeping all of my power and energy saving features enabled (i.e. Speedstep and C1E)

The latest release of CPUz is compatible with your board and the 2700K, so I don't think it's an issue with CPUz, but an issue with the way you have your BIOS set up.

As for the vcore shooting up to 1.40v under load, that is a result of Load Line Calibration. Play with that setting until you find the sweet spot that yields a small vdroop when going from idle to load. Say your idle vcore is set to 1.355 - you want your load vcore to be at that or lower by .02 to .03v - most folks recommend against a LLC setting that yields a higher vcore under load than what is set in your BIOS.

Glad that you're getting it sorted out and glad to have helped. Best of luck.

On another note, overclocking the Z77 is akin to overclocking the Z68 is akin to overclocking the P67. Same methodologies pretty much. And there are a lot of OC guides around for those platforms. Especially true for Asus boards. Read a couple of them, then read again.

The rest is just trial and error, practice, patience and learning alot on your own.

Again, best of luck.