i was using the same CPU at the same overclock for awhile (waiting for my new coolmaster v6gt before i overclock properly). my idle times (when my cpu was doing nothing much) were about the same temps as you but with my STOCK COOLER!!!
The heatsink and fan you are using appear to be pretty good, I think maybe there is something wrong if that is your idle speed?
Obviously it does, as zipzoomflyhigh says, depend on many other factors like room temperature, cooling inside the case etc.
If that temp is under load, then its amazing! its pretty much what you could expect from a cheap water cooling solution!
Other things to consider are the temperature of your graphics card they can heat a case up like an oven in about 30mins when playing things like crysis. Also memory temperature is important. for me with a water-cooled system in the past, i could keep the cpu heavily over clocked yet never more then 48C, but the memory would get stupid hot (could not touch it was so hot!!) and that would cause a BSOD.