read the stickies. They will have some voltage info.
temp monitors. Hwmonitor, reatemp, coretemp, CPUz. Watch the temps for a while when you start prime95. If it starts cooking, stop it.
be carefull not to over OC the other settings. For example: turn off autosettings for pcie frequency. Manually set it to 100. When you up your fsb, it will auto adjust your other auto settings. This can cause issues. I set everything manually.
try to set your DDR2 ratio at 1:1 or 1:2. for example: 400fsb:800mhzDDR2.