OK,
334FSB is stable at core volts at temps 54/54/50/54 (why is core 2 always lower?)
If I jump to 3.2Ghz I start to run into problems, there are a variety of Volts to adjust in bios, so I upped CPU (and RAM) by the min margin, but still get errors as soon as prime starts.
I don't really know which volts to what, and what ones I should fiddle with.