I tried the ClassXX.rom, installed the 'new' PrecisionX (mentioned by KingPin), enabled K-Boost (made sure to disable SLI first) and I can't get even a slight OC!
My cards run all day on the stock bios @ 1580Mhz.
I used the Classified Tool 220.127.116.11 and put the voltage at 1.30V and Heaven freezes at 1604Mhz!
There must be something I'm doing wrong.
Any advice is appreciated - one of my cards is 80.4% and the other one is 87.7%!