Good luck. That board is definitely not designed for OC'ing. And w/o an unlocked multipier, your CPU will only get a couple hundred MHz bump at best from boosting the base clock. If your board and PSU hold up.
I doubt that board even has options for OC'ing the CPU.
If you need more gaming power, the old Athlon dual core can still keep up with a bit more gfx card if you want to upgrade that.