**UPDATE**
Got it fixed using osx86tools. For anyone else having problems here is what I did:
Open osx86tools
Click "Add EFI Strings/Boot Flag"
Choose GFX strings (top left)
Choose custom geforce hex at very bottom of cards list
For name input your card. Example - nVidia GeForce 4800 GS
VRAM size: 512 (or whatever yours is)
Output config: DvI-I/VGA (again, whatever you have)
Then choose "Import string to boot editor" at top and then apply at bottom of next window.
That's it. Hope this helps someone.