I do the pencil mod 1,44V and so i can run the 900+ core. (Wathercooling)
Maybe your core can get more Mhz without higher voltage.
I think itīs not normal that i can go so high clocks. I had a little luck with the Card.

You can go wth your mem to 1185 now? Wow, mine goes currently only 1125 but is stable.

I send you an PM