Overclocking E8400 processor, need help

I have mounted Intel Core2 Duo E8400 processor on a Gigabyte GA-EP45-DS3 with 2 x 1GB of Kingston HyperX PC8500 (voltage upto 2.2V).

I am trying to raise my E8400 in stages. I must say I am quite surprised because I have touched an exception of RAM to function at 3.2 x 333. I tested each time under OCCT.

My approach I kept the coefficient to 9 and raises the FSB gradually, for RAM I spent the coefficient to 2.4. The results, validated by OCCT 1 hour without error:
FSB 380; 390; 400; 410 -> OK
For temperatures: I am 42 in idle and the temperature tops out at 67 °C burn. These are 67 °C maximum temperature reached that I am at 390, 400 and 410 in FSB.

I am at 3.7GHz with default. Thing that surprises me the most is to have a FSB of 410 without having touched the Vcore!

Now what I want to ask is that:

1. How should I proceed now, continue to increase the FSB without touching the Vcore? when will I see that the Vcore will no longer be enough?
2. For the temperature: 67 °C in full is not at all too high? I will change the fan but I do not know what apps will take me there, in your view?
3. When to overclock my Radeon HD4850, I have already used the utility catalyst control center, but this one tops out at 700MHz while it is stable at this frequency? What software utilizes you to validate settings?

Few things that I would like to share:

• In E8400 rev E0 (before it was C0 which was less preffered) amount generally well VCore of origin.
  
• the best type 4GHz @ 1.17 V VCore
  
• Did you set the value of VCore in bios or did you put on auto? VCore attention that does not fit for o/c
  
• 67 °C is the max temp if it goes on the hottest core. perhaps a bit too if the CPU temperature
  
• to mount o / c then we must mount the VCore and there, to dispel the calories increase with the square of the progression of VCore. it is necessary to change heatpipe and put a preference. they save you a good 10 °C on the temp max

Thank you very much for all these details.

1. After checking in CPU-Z, It is a rev E0
2. Ah, but right now I don't have a super box.
3. I did not set the value in the bios, but check it on graphs OCCT, it remains to 1.17 V.
4. The two cores are at the same temperature, so the temperature recorded in OCCT and confirmed by CPU temp, in fact I dare not go higher yet because of that temperature.
5. OK is clear!

The final test is to change Vcore to 1.20V at the starting point of OCCT in bios but it is 1.2375V.

I continued to push the FSB, but the breakdown of my size limit myself clear!
I spend a FSB of 430 with T max of 62 °C in full box open. As soon as I close the box, the températiure climbs to at least 70 °C (I had stopped the test before).

Summary,

Core2duo 9 x 430 = 3.87 GHz
RAM 2.4 x 430 = 1032 MHz
Rated FSB 4 x 430 = 1720 MHz
CM T = 54 °C (that is a liability on the DS3-EP45)
Core1 and T 2 = 62 °C