I've been running mine at 3.83 for months. Not one hickup. I think vcore is 1.27 if the utility is reporting it right. I didn't raise the NB voltage. Anyways...
First thing I'd do is put your ram at like 2v 667 5-5-5-15 where you know as a fact it'll be stable. This would eliminate the memory as the cause. Work on the CPU alone. When you try to o/c everything at once you have NO IDEA where your instability is coming from. Make ONE CHANGE AT A TIME. Start with the CPU first. Raise the fsb ONLY until you become unstable. Next raise the vcore a tad to see if that stabilizes the system. If not, put the voltage back and then try raising the NB voltage. Stabilize? If so, go back to raising the fsb some more. You have to work each variable one by one to work things up to speed. You can't just crank it all up and hope.