You might as well get more performance. Youl be surprised how much a CPU overclock improves framerates.
John, I thought you are using an E8400? Why is it only running at 3.13Ghz? That thing runs 3Ghz stock. Unless youre running another CPU. In that case, why? I thought you bought the mobo for your E8400
Bump up the voltage a notch and increase your fsb again. Its generally safe if you keep your increase in voltage less than 10-15% of the stock.