I'd be in for this also, after installing my 780 classified HC's most of the stock block isn't visible, so while I liked the look of it, it's hidden anyway, so something that will add a little more cooling to the system would probably be a good idea. :D
If it would help at all nateman_doo, I can send you any measurements you need (have calipers) of the area with a 780 HC + Backplate installed with an EK Supremacy CPU block installed.
Let me know