Should be somwehere in the BIOS. Sometimes you don't see it because you have to change an option to "Manual" instead of "Auto", and then the options to change timings appear. Poke your BIOS until it works .
Edit: Also, I'm curious: what's your SuperPI 1M time? I want to see how an overclocked X2 4200 compares to an overclocked E6300.
Edit: Also, I'm curious: what's your SuperPI 1M time? I want to see how an overclocked X2 4200 compares to an overclocked E6300.