I'd love to do this to my QX9650, but £450 is a lot of cash to be playing with... maybe later in it's lifetime. Add to that the worry that even with the shim, I'd be worried about the weight of a TRUE 120 hanging off of it. I'll probably wait till I can afford a watercooling setup, I'd imagine the pressure on the die is much more uniform with a small waterblock, rather than a huge heatsink.

Great job though mate, nice result!