New Tool
VBE7 Tool, Created by darkhmz with the help of (DroiDMester)
Notes about this tool:
Like the other tool it flashes the whole voltage table, so its very card specific for the clocks that you set it up as. Also it changes the checksum when modifing as well, so if you have a blank screen when rebooting you will need to go back and edit your checksum for the bios in order for it to work for you. Cards such as most XFX cards will need the checksum modded and others using newer motherboards which has a form of hash check for the gpu will need it as well. But overall its very simple tool to use. Does not work with 7790 cards at this time.

With this tool you will be able to
Change Vendor ID / Subsystem ID (not recommended)
Change clocks and voltages
Change OverDrive's core clock and memory clock limits, TDP limit, power limit
Make custom fan profile

There are some limitations though...
You cant change 2D / UVD voltages
You cant set 2D / UVD clocks higher than the values stored in BIOS (these limitations are intentional, without these limits powerplay would go nuts...)
The following voltage regulators are fully supported: CHL822x, CHL8214, UP1637, UP1801, ST6788A, VT1556M
For unknown voltage regulators, you can select voltage from a predefined table.

How to use
Save your BIOS with GPU-Z
Open with VBE7
Modify
Save
Think twice before flashing
Flash your modified BIOS either with atiflash or atiwinflash (preferably atiflash) and use the -f parameter to force flashing
Reboot

Please read the following before you give it a go
This is a new software so even though it worked for me and some others, i cant guarantee it will work for you as well. USE IT AT YOUR OWN RISK!
Dont forget to make backup of your original BIOS
Use it only if you know what you're doing, and if you can recover from a bad BIOS flash if something goes wrong...
This software is not foolproof, use it carefully
Modifications only affect the legacy BIOS, and after saving, UEFI image will be disabled (in case you have UEFI vBIOS)
If you're experiencing problems with your modified BIOS, please post your original and modified files.