Ive got my e6600 at 8x425 (which the the multiplier you have) @ 1.375v. I set my HZ's to one-one divider (those things overclock like beasts....i have them set to 2.05v with a minor overclock when their supposed to be set to 2.1v
Basically go into bios and set the Ai tuning to manual and have fun
This should help you out some: p5b-deluxe overclocking
I have my pci express freq. set to 100 though so you shouldn't need 120. And just start with a minor overclock that doesn't need the vcore changed and work your way from there. I was shooting for 3.6ghz on my e6600 but i settled for 3.4ghz since i didn't like the temps i got at 3.6ghz.
Hope that helps you get started