GPU0 64C Sol/s: 279.7 Sol/W: 3.49 Avg: 277.9 I/s: 146.8 Sh: 0.00 . .
GPU1 63C Sol/s: 280.4 Sol/W: 3.50 Avg: 280.0 I/s: 147.7 Sh: 0.00 . .
GPU2 64C Sol/s: 272.3 Sol/W: 3.44 Avg: 274.2 I/s: 147.6 Sh: 0.00 . .
GPU3 69C Sol/s: 274.8 Sol/W: 3.40 Avg: 271.6 I/s: 145.9 Sh: 0.99 1.00 104
GPU4 66C Sol/s: 282.2 Sol/W: 3.49 Avg: 276.2 I/s: 147.4 Sh: 0.00 . .
GPU5 60C Sol/s: 281.9 Sol/W: 3.51 Avg: 279.6 I/s: 148.9 Sh: 0.00 . .
GPU6 67C Sol/s: 298.0 Sol/W: 2.71 Avg: 293.5 I/s: 156.9 Sh: 0.00 . .
> GPU7 65C Sol/s: 297.4 Sol/W: 2.72 Avg: 294.7 I/s: 158.4 Sh: 1.98 1.00 114
========== Sol/s: 2266.9 Sol/W: 3.28 Avg: 2247.8 I/s: 1199.5 Sh: 2.97 1.00 109

This is with 6&7 turned up to your settings 150/1100/110 as they seem to be the best cards, but still top out at ~300Sol/s.

What do the numbers in your rig list look like?  For some reason the memory clock numbers don't change even when I change them in overclock settings, maybe that's my issue:

This is what my Core/Mem column looks like:
1721 1733 1695 1733 1708 1733 1911 1961 (80,80,80,80,80,80,110,110)
3802 3802 3802 3802 3802 3802 3802 3802

The Memory numbers on the last two should be higher, since that is how they are set in the OC settings, but you can see they don't change like the core numbers do.