Interesting idea; but, space is pretty tight. There's just about 8mm between the radiator frame and the power supply.could a 3d print 120 to 140mm adapter possibly work so you dont have to drill the case?
But now you've got me thinking... and one could probably print a small, simple part that would accommodate a nut on one side and a countersunk screw head on the other. Such a part would only need to be 3-4 mm thick. Four of those and you have an adapter.
Hm... If I came up with that idea so easily, perhaps this has already been done?