Chris,
Awesome rig. I decided to split mine into two PC's since I did not want that much heat in my box. But then again I am only running 3 cards. 4th card when a 1080TI comes out or the next best thing.
Interesting thing is a left everything stock. Main machine 1080 is at 1934 clock, 1070 at 1979 clock. Living room machine 1070 at 1911 clock. So cooling and silicone luck it seems to be. The living room machine may be slower since it is running the monitor for that machine.