It probably overheated because the mosfet sink was bowed after the Cascade mount was tighten, I will uninstall that sink and use some individual cooper sinks on each one.
I was only at 1.70vcore / 1.80pll / 1.60vtt w/ the Q6600 @ 5Ghz running wPrime 32m.
DOM it was a Ep45_ud3.