I have a similar build, except with the GTX 770, and managed to get it to work this weekend.
On my first go-round, it didn't work since I was using the original Mavericks installer (10.9.1?), and I kept getting the black screen that went nowhere. Once I downloaded 10.9.4, it liked this, along with the -v npci=0x3000 cpus=1 -f option mentioned earlier in the thread.
I didn't experience the exceptionally long pauses during boot ups, perhaps a minute at most between getting to the bright gray screen to getting to the darker gray screen, so that was reassuring.
Interesting note: the network adapter worked out-of-the-box, until I ran multi beast, then it stopped working. (I didn't select a network driver, since it was working). So I had to use Multibeast to fix it after the fact, and although fussy at first, seems to be working okay now. I wonder if I should select one of the more recent network drivers, than what was originally recommended in this thread?
Most everything else worked easily as well, including the GTX 770 out-of-the-box. I was glad about that, and it's very beautiful to behold!
However, my last hurdle is to get the audio working. I tried switching to the Chameleon boot loader, but this didn't solve anything for me. OS X says there is no sound adapter in my computer. (It works fine in Windoze, of course).
Are there any other suggestions for getting the sound to work? Naturally I selected the ALC892 adapter in multi beast, and as mentioned, I installed Chameleon later. No luck so far.
Thanks in advance!