LSUToo swears all Haswell need to be delidded.
I only say that as an OCing enthusiast, but it really doesn't need to be delidded, IF you get something better than the stock cooler (and I know you will). I was helping TigerfaninHTown do some OCing on his Haswell, and we got him at a safe 4.1-4.2GHz using a hyper 212. Temps in AIDA/Prime were in the high 70s and probably would've jumped in the 80s under an even more unrealistic load, but those CPUs are built to do 90 all day long and throttle at 95.
And that's the 4770k with hyperthreading enabled. 4670k will probably run a few degrees cooler.
I'm just saying, don't expect to be swinging massive e-peen with a 4670k overclock. But at stock, there's still no other CPU with better core for core performance at that price point.
This post was edited on 9/6 at 4:25 pm