First off, I admit that I do not have much experience with watercooling a graphics card and I am just using my knowledge of watercooling a CPU.
Now, I have gone through your build log of your graphics cards. Check this video out. It is Skinnee's installation of an EK waterblock onto a GTX480. Go through this 9-minute video guide and use it as a reference to check your own installation.
One thing I do notice from your build log is that you did not document that you took out the water block after the initial put on to check the spread pattern
of the thermal paste. A good uniform spread points to a good contact between the block and the GPU. Did you do this check or not?
One more thing:
From the screen shot in the OP, I notice that for GPU1, the temp is 86C while the fan is only at 50%. I wonder why the fan spins so slow at such a high temp?
I suggest you to setup a custom fan profile
to speed up the fan.
And, do this for both
Last thing: I scan through your PC build log as well. Very nice! Once you get this thermal issue sorted out, it will be awesome.