Looking at MB specs, it supports at least 125W processors so it shouldn't be a problem to at least 4GHz at 1.4v but stock cooler may be biggest hurdle.
Your processor is 95W so there's a lot of room for OC. In my experience, couple of 100 MHz OC is practically invisible but you can try raising CPU multiplier a notch or two until you have to raise voltage for stability and temperatures stay in decent range.