It is normal for one core to fail before others, yes. There will always be a weakest link. It's extremely unlikely that they will both fail at the same time. If it's failing, your OC isn't stable. You may need more voltage.
I haven't OCd an AMD, but I'm assuming that's pretty universal
^okay, i thought so. i bumped up the vcore to 1.35-cpuz showing 1.37 idle 1.39load and i tested prime95 it was stable for a few hours before i shut it down. i'm gonna let it go overnight to see what happens. thanks