The following settings are known to support an E8400/E8500 at 4.0ghz and above. Again, the latest BIOS is still finicky when it comes to 45nm chips, so you may not have guaranteed success just yet.

FSB: 1800mhz
RAM: 900mhz

vCore: <<entirely dependent on the OC capabilities of your cpu.>>
vDIMM: <<entirely dependant on your RAM. Set to maximum factory setting.>>
vNB: 1.4
vSB: Auto
FSB Term: 65
All other voltages: AUTO

GTLRef doesn't seem to play as large a role here, and it shouldn't, considering it's concern is more with Quad Core cpus. Compared to the Q6600, the key difference here appears to be FSB Term. 65 (vs 25) seems to be the key for E8400s OCs on this board.
Someone has gotta change the information on the first post in the thread about someone having success with the E8400 with the FSB Term set to 65.

First of all, the FSB Term only goes up to 63 doesn't it? And second of all, any way you slice it 63 would've fried his processor.

If it's 1.xx. Then 63 would be 1.63 volts. That's over the 1.45 volts absolute max for Penryns.

If it's 0.xx added to a base value... It would still be too high.

Someone is going to read that first post and not read the rest and fry his processor.

Better include a warning underneath that.