That's exactly where I'm at with my 2500K... 4.1GHz with a CoolerMaster 212+ w/dual fans.
At full memory load using LinX my temps top out at about 72C... this was after I reduced vCore .08v, otherwise it was running at almost 82C.
In hindsight, I probably didn't need the second fan on the 212+, I think the real trick was backing the voltage down. As soon as I go above 4.2GHz I start having trouble... and it's not worth it.