LGA 2011 Cooler Compatiblity(Gutting an HP and putting it into a new case).

I am currently rocking a prebuilt HP ENVY Phoenix 800-070st (I know eh prebuilt computers). I've been into computers and computer building for a while helping friends with their own systems. Recently I've decided to finally update my system by swapping out my gtx 660 with a gtx 970, then I decided I would like to change the case itself so I have decided on a fractal design r5. My processor is an i7-3820 sitting on an HP based X79 motherboard(Pegatron based board: IPIWB-PB, codename Pittsburgh2) with 16 gb of ddr3 ram. So I'm thinking to myself sweet why bother spending 300-400 dollars on a new motherboard and processor when I have this killer ivy-bridge. The computer comes pre-liquid cooled with an AIO, but I'd like to make the transition to an air based cooler like the Dark Rock 3. And here comes the main concern so far I have read that the LGA 2011 coolers work with LGA-2011 V3 but is it the other way around as well. The current HP cooler is loud so my goal with this system is to make it as quite as possible. Any advice on the cooler compatibility would be great, I'm mostly worried about the back-plate installation and how important that is with that particular cooler.