Every processor is unique in it's voltage tolerance, thermal behavior and overclocking potential, however, the typical overclock for the i7 920 using your case and proposed cooler is 3.8 Ghz. If your luck of the draw is exceptionally good, then you might receive a processor that is capable of reaching 4.0 Ghz without exceeding Intel's Vcore or Thermal Specifications.
Vcore Max = 1.375
Tcase Max (CPU temperature) = 68c
Tjunction (Core temperature) = 73c