Hey, I'm running my 7600K at 4.8Ghz stable w/ 4.4Ghz cache @ 1.35v on the Hyper 212 evo/led temps around 65-75, using Arctic Silver Ceramique. I benchmark at 4.9 stable but need a little more voltage, so I keep it at 4.8 and am more then happy. (Going Liquid Soon)
I'll be printing the delidding tool soon and then it can only get better! Works great for stream transcoding on twitch while playing simultaneously. The extra 1Ghz helps!
4.2 on the stock cooler is doable, with the 212 and good airflow, you won't have any trouble.