There was a monitor forum that had a few people do it. I forgot which one it was, hence why I can't directly link them. One of the people from this forum did a review on it and has been running 120Hz since then (I was reading this forum a few weeks ago). If I can find it, I will link it, otherwise this is all I have to show:
You can see in page 2 that they have the multi-input version and through the comments, HDMI could not overclock, but the DL-DVI worked for both monitors.