2700 is mildly OC'able,,
I have mine pushed up a bit,, just remember to bump the voltage slightly,,,
You should be able to play around with the soft menu on the ABIt board,,
True you wont be able to get HUGE gains,, but you have some quality ram,,,
I would check the sites for compatibility between the two,, and make sure that you find a level that is optimum for BOTH sticks,, not just one,, and not the other,,
Kingston and Crucial,, although both quality,, have different thresholds to be aware of ,, most manufacturers put out a compatibility list now,,
check it out,, and start clockin'
cheers,