help! e8400 voltage and temps!

Hay,

Ok, i'm overclocking my e8400, and i've got the ga-p35-ds3l motherboard, and one thing i noticed is the vdroop. I want to overclock my e8400 to 4,2 ghz, but in order to acchieve this, i need to set the voltage in the bios to a whopping 1,5! And when idle, cpuz shows 1,472, at full load, orthos, cpuz shows 1,440. And 1,440 isn't very high for 4,2 ghz. Legionhardware overclocking guide for e8400 needed 1,45 volts to achieve 4,2 ghz. But i'm worried about the 1,472 volts at idle:S wat should i do? should i back up to 4 ghz? or should i leave it this way?

And by the way, my temps, when full load using ortos, coretemp gives me:

core 1: 69/70
core 2: 68/70

and speedfan gives tcase: 59/60

But here's the problem, the tempguide on this forum said that the difference between tjunction and tcase should be somehing like 5 degrees, but mine is 10:S?

And another thing, onder full load, both core temp and everest ultimate show:

core 1&core 2: 69/70

but realtemp shows: 60/61

Realtemp gives the same readings as the tcase temp from everest and speedfan..

So wich temps are real? and do i need to worry?

My cooling is: Zalman cnps 9700led.

So should i back up to 4ghz for safety, or is it already safe?

idle temps:

core1/core2: 40/41
tcase: 29

thanks!