Although I know airisom doesn't recommend it (I do) you can try this:
Uninstall all codec packs/ media players/madvr/lav/ffdshow. Restart your computer for good measure.
Download the test build of KCP (it's perfectly stable): http://haruhichan.com/forum/showthread.php?7545-KCP-Kawaii-Codec-Pack and install it. Might as well choose the highest settings, your system is comparable to mine and should be able to support it easily.
Run a few test videos. Is everything running nice? If so, move onto SVP.
Install the latest versions of SVP, avisynth, and VCRedistx86. Then install the latest stable (and only stable) version of ffdshow_tryouts.
Now, with SVP manager running, retry running the video. Everything should be the same as before - no interpolation. Right click while the video is running, and go to the filters list - make sure no ffdshow filters are running. If any are, make a note of them.
Now go to the MPC-HC external filters page (in the main options window). Block any ffdshow filters that were running earlier, and set only "ffdshow raw video filter" to prefer. For good measure, you can add the LAV filters and set them to prefer.
Now double-click on the ffdshow raw video filter from this page and the ffdshow configuration page should come up. Untick all the boxes in the left pane, and then tick "Avisynth".
Now right click on SVP manager and make you you have the most advanced (maybe called expert) view. Enable GPU Acceleration. Rerun the video and alter the relevant profile settings to what airisom posted before. If those run fine you can tweak SVP settings, otherwise try only interpolating to 60Hz and see where your GPU usage sits as this could well be the problem.
I'll post my own results when I get back, but I know getting madvr Jinc3 to scale up 120Hz 720p anime nearly maxes out my 7970 @1100/1550.