Given that Gigabyte hasn't even been really gung-ho about overclocking until now, I'd wager not. If there was a modified BIOS for the board by some 3rd party, it might be an option. If you're gutsy enough, you could get a BIOS image editor and fiddle around with that.
But, under the norm, no, a BIOS image from Gigabyte will most likely not allow over overclocking.
You might try hitting [Ctrl]+[F1]. Gigabyte has been known to hide extra settings that aren't accessible without unlocking them like that.