Apparently it's a special order:
"The mounting hardware for the H50 will allow it to be mounted up to LGA775 and LGA1366 CPUs. Now, even though our review kit came with the mounting hardware for an AMD system, the instructions state, “For AMD mounting system, please visit Technical Support Express and www.corsair.com to order.” So, that leads me to think that the retail kit will not have the AMD hardware in it." http://www.legitreviews.com/article/1025/4/
It looks like you have to remove the amd clip and install their backplate.
But already I can tell it's doodoo. You need 160+mm of fan for watercooling to be better than the top HSF's.