All the LGA2066 processors have unlocked clock multiplier, which means you can overclocking it just by changing its multiplier, as long as the motherboard has this feature.
We were able to configure the CPU to run stable at 4.9 GHz (100 MHz reference clock and x49 multiplier), with the original voltages. Raising Vcore to 1.3 V, we were able to run it stable at 5.0 GHz, which is a great mark. It may be possible to reach higher frequencies if you “play” with the available adjusts, as long as you have a good power supply, motherboard, and cooling system.
It is also good to keep in mind that the overclock capability depends on pure luck, since two CPUs of same model can reach different maximum clocks.