With that much V going through the 920 (provided you have the D0 stepping) you could clock that thing all the way up to 4 - 4,2GHz provided you have the cooling.
Basically at that 1,4V you're hammering through it, is likely a cause for overheating as even with heavy duty cooling, mine still rises to 76 degrees C on 1,3875V.
Get a better cooler with a new application of Thermal Paste, should solve your issues without problem.
And make sure to clean your case of dust once in a while, don't use dustbusters etc though.
Preferably a compressed air/nitrogen can, if not a standard compressor will do provided it's not 30 Bar to blow a hole through your mobo.