My 680i board may not require the same voltage settings as your eVGA board, but I have noticed that for this chipset, they are understandably close. Maybe you can achieve the 3.6Ghz target with an "Auto" Vcore setting -- maybe not. I can't. Further, I had to adjust the CPU_VTT voltage to 1.45V (BIOS monitor reports the sensor reading of 1.39V). This is the limit mentioned in a brief comment by Anandtech "techs" noting that a VTT voltage that is too high will kill your Wolfdale very soon. That is, according to the Anandtech article, the actual voltage should not much exceed 1.45V, and that 1.5V or higher will profoundly increase risk of short processor longevity. And it had been shown with the earlier 65nm Conroe processors (C2D and C2Q) that you definitely had to bump up the CPU_VTT voltage as you move toward and past a CPU_FSB speed of 400 Mhz. 400 Mhz is exactly what you need to get 3.60Ghz, or multiplier-9 x 400 = 3600 Mhz.
But with my ASUS Striker Extreme 680i, I had to manually adjust the vCore voltage, which is currently set at 1.32+V. My setting was chosen as that which provided rock-stable Blend Testing with PRIME95 for about 14 hours -- at a speed of precisely 3.645 Ghz. This setting was 5 Mhz higher than the CPU_FSB value of 400 Mhz needed to obtain 3.60 Ghz (or 9 x 400) with the E8400 processor.
Anyone may differ, or say that I'm offering snake-oil here, but you'd probably want to look at the thread started early this year asking people to post their results with the Wolfdale processors. That will give you a ballpark estimate of vCore settings across a range of motherboards, and you can narrow down the range to "all 680i motherboards," and even to the eVGA.
Keep in mind, though, that different BIOS revisions may change slightly the "set" voltage you choose in the BIOS menus to get the processor and board to run stable at that speed. There is always a discrepancy between the BIOS monitor reading of the sensor, and I think it is a safe bet that the discrepancy varies with BIOS revision and board manufacture, even if a 680i chipset is common between boards, or a 680i reference design is common between them.
The thread in question may provide a good guideline, keeping in mind that some people may exaggerate their results, fail to stress-test for a significant length of time, or fail to set the vCore to a minimum necessary to achieve stability.