Ok, here is a quick guide on how to check which timing set your NVIDIA 6xxx/7xxx uses.
You need the PC video card in your PC that you want to flash,
its PC video card ROM, NiBiTor, and Proper drivers installed.
Open NiBiTor and goto file>open.
Select your ROM and open it.
Go to the "Timings" (arrow).
Select "Autoselect timingset" (arrow).
Where the blue circle is you should see your card, Now select it and hit ok.
A window should pop-up saying which timing set is being used.