3Ball, you got GREAT results there, well done!!!
Yeah, if running into stabiliity problems, then definitely bumping up vcore, vdimm almost always solve it.
In general, for just about any overclock on a DS3 that isn't insane high, vCore to 1.35, vdimm to +0.1v (or maybe +0.2v), vMCH +0.1v almost always works and is stable. There are exceptions, but I've had it work too many times to argue LOL.
However, the goal is to always get the volts down to what is still stable, so 1.325 vcore might even work. But those settings I just said have almost always worked on just about any C2D and a DS3, so it's the best starting point.
Just gotta make sure EIST, C1E, etc, etc is all disabled and PCI is locked to 100.
Do all that, and you're almost guaranteed to hit 3.0 ghz without breaking a sweat........ASSUMING you have some decent cooling. DON'T FORGET THE COOLING!!!!!!!