I7 920 OC without increasing voltages - Some doubts

Gday Guys!

MY SPECS:
Core i7 920 @ 3.5Ghz
Stock Cooling
6GB (1333Mhz) Kingston RAM
Intel DX58SO (Smack Over)
2x GTX280s SLI
1000W PSU

CONTEXT:
I only have stock cooling, therefore I thought it best for me to avoid changing any setting that would increase the temperature.
I read somewhere that changing the voltage is what leads to problems with meltdowns.
I have read a few articles and watched a few OC videos, but it seems that the instructions in these things are aimed at those who want to do OCing in the order of 4Ghz (this is not me).

WHAT I DID:
1) Entered into the BIOS.
2) Changed the Host Clock Frequency from 133 to 165 or something.
3) I noticed that my RAM speed automatically updated. (and I made sure it was under 1333Mhz (its rated speed)) It's voltage did not change also.
Both Hyperthreading and Turbo are Enabled.
Everything is stable.

I do not know if what I have done is bad for my CPU and need advice on it.

I have done three Prime95 tests (uncalibrated) from Stock settings (with Turbo Enabled) up to 3.33 Mhz.
The max temp at CPU usage of 100% was around 84degC in ALL cases.

The temperature relationships and magnitudes from the Prime95 Tests are pretty much identical.

2800Mhz

3031Mhz

3382Mhz

After playing ARMA2, my max temperature was recorded around 64degC both stock and OC.

QUESTIONS:
Because I havn't mucked around with memory multipliers and all that other business, am I damaging my system? (I mean is there something I am missing that, when ignored, is detrimental to my system?)
Since the temperature relationships between stock and overclocked settings are the same, does it mean that I have made a safe OC?

I intended to reply to the OP anyway his temps under load are to high to suit me for long term. I would try for 70 as max core temp. OP needs more case airflow, or better heatsink. If it will fit in your case the thermal right IFX 14 or the 120 ulta can't be beat with a good 120mm fan on them. Good as some cheap water systems. I am running my I-7 920 at 3.6 stock with only bus speed increase. I see Mid 60's C with a IFX-14 and a admitidly loud 3800rpm 120mm fan. The case is a haf932 coolermaster with the 3 stock 200- 250mm? case fans. It takes good airflow with air cooling to be efficient. I plan on going to water later and open the throttle up.