I switched my cooling over to water from air... (Alphacool NexXxos UT60 triple rad with XSPC RayStorm block). I was hoping to break into the top ten and I might be able to tweak a little more out of it but it seems like ~5.2(+) might be close to the max on this one without going cold.

I'll try to do some more fine tuning but here is what I've got now...