#Rotor & Got Karma: Yes, my thought was to secure it to one drive and then use the cage as a clamp to hold the other drive on TOP of this with the bottom drive upside down so the water block is facing up. This would force the weight of the top drive down on the block and also cool it too. (In theory)
ralf_c: This block does screw to the holes on the bottom of the drive, just two of them... otherwise I would have made it narrower.
I did find out one flaw with my design. The motor area is slighty lower than the sides of the drive casing. So I had to go back and mill notches to the ends. Like so...