I'm not sure what you said, or are trying to accomplish. But you are not changing the correct fields.
Don't change any of the voltage fields under GPU/RAM speed. Leave those alone. You need to change that correct voltage registers. Also, you don't want to put 3 volts in any of those fields.
Here's which voltage register and it's corresponding clocks speed modes they work for:
So if you wanted to mod your bios for higher 3D clocks, and change the voltage so it's stable, you would increase the value of register 0x18. But you shouldn't really be messing with things until you overclock and change voltages in windows with afterburner, or other tools. Once you know your stable 24/7 settings, then you change your bios if you want.