I7 920 @ 4.2 safe?

So I was looking for a guide to OC my EVGA x58 and found this

EVGA x58 OC guide.

I'm new to overclocking and somehow 4.2 on air kinda scares me.
I followed the guide almost verbatim except where he did 200 to get 4.2 I did 175 to get about 3.6.
Everything else voltage increases etc I did and it seems stable but I would love any opinions on this.
Last thing I want is to blow a brand new CPU.
I'm running it in a Antec 900 with an extra 120mm fan on the side so its got plenty of airflow but better safe then sorry

Just have to watch the Vcore on air over 4Ghz.

i'm running 3.8 on near stock voltages for what it's worth--1.21250 vcore, 13 hour prime95 stable. I think I ran really good on my processor as I hear a lot of C0's needing much higher vcores. My temps aren't as outstanding as you would think though...idle 39-43 depending on how warm my room is and near 80 under load (with HT on)