You should be able to.
This should be your first stop.
Core2 Overclocking Guidehttp://www.tomshardware.co.uk/forum/259899-11-core-overclocking-guide
Shadow's Gigabyte motherboard OC guide:http://www.tomshardware.co.uk/forum/page-245679_11_0.html
It's for an EP35-DS3L but all the Gigabyte Core2 BIOS's are similar.
Keep in mind that both guides are for motherboards using DDR2 RAM.
Go through the guides. Then take your core voltage off Auto and set your memory voltage to factory recommended values. Change the System Memory Multiplier from AUTO to 4.0. Then when you increase the FSB, the memory clock will rise in in proportion with it. At an FSB of 333 MHz, your memory clock should be at 1066 MHz.
Download CPU-Z to check your FSB:RAM ratio. It should be a 1:1 ratio.
Now start the "increase FSB, test, and increase voltage" cycle.
Your memory may limit your overclock if you have DDR3-1333 RAM. You can try relaxing the timing one bin (like from 7-7-7-20 to 8-8-8-24 or something similar depending what the original timing numbers are. You can also try running the RAM voltage at a max of 1.65 volts.
Do not exceed core voltage of 1.45 volts, keep your load temps under 70 C., eat your vegetables, and have fun.