If you look at the backplate of the h100i cooler, one side is slightly skinnier arms that go across to the holes of the socket. That side must be on the side where the two screws are on the back of the socket in order to not have uneven spacing.
Example:
http://cdn.overclock.net/a/a7/350x700px-LL-a71b1057_backplate.png
Also, 1.3V on Haswell is on the higher side for a 4.3 OC, it appears you didn't win the silicon lottery.