What do I change if I fail prime95?

It's likely a NB or SB related fail.That happend to me when i tryed to O.C. my NB.Ran Prime and it failed and would keep testing core 3.Increasing the voltage won't do it,it's more of an internal error or prime.Try using a different stress testing program.
 

The simplest thing is to try a small vcore increase. But when you start increasing voltages, you need to really monitor your temps.

Adjust your RAM settings so you have your memory clock twice as fast as the FSB freq. When set up properly, CPU-Z should tell you that your FSB:RAM ratio is 1:1.

There's a lot of other CPU related settings that you can try, depending on your motherboard. But at this point, your overclock does not lend itself to a "cookbook" approach.

And it is quite possible that you have reached the limits of your CPU.