E0 CPUs supported on IP35

I have an IP35 Dark Raider (not E/Pro/XE etc) with a C0 stepping E8400 at the moment. It's currently running at 3.6Ghz (400x9) @ 1.285v giving 44C idle and 62C load (measured by RealTemp). I'm still testing how far I can push the CPU, but the temps seems a little high for the voltage and speed, so I was thinking of switching to a cheap E0 cpu from ebay. My hope would be that the later stepping runs cooler for a given voltage and speed.

I'm currently running the v18 bios, and I'm aware of the beta E0 one that is supposed to add support for the later stepping, but I have read mixed reports about how well the updated cpus are supported on this board. Could I run an E0 E8600/E8500/E8400 in the IP35 with the beta bios? Some reports suggest that FSB changes work but Vcore ones do not. Others mention things like incorrect temperature readings, but are unclear on exactly which bios version they are running.

Is anyone out there still running this board with any of the E0 CPUs? Or have had experience with them in the past?

Thanks in advance.