If the monitor and VC support it then yes it is possible. Do you want to do it is a better question.
The answer is that you may be trading away image quality unnecessarily. To make a black and a white pixel next to each other, the electron beams in the monitor must go from off to on in an incredibly short length of time. If there isn't enough time for the change, the transition between the two pixels goes gray. If you are speeding up the refresh rate, you are giving the electron beams less time to switch on or off between pixels. So the best approach is to choose the lowest refresh rate at which you can't see any flicker. To check, look about 6 inches to the side of the monitor while a white screen is displayed.
Chief Hardware Engineer
Cornerstone / Monitorsdirect.com
Jim at http://www.monitorsdirect.com