Nice find! I didn't envision something that deep, so that will help quite a bit. How do you plan on insulating it?
Did the seller say which model Cray it was from? The older units were typically were submerged in a few tons(!) of 3M Fluorinert with chillers at the bottom of the chassis, water cooling for them would be much more modern (last 10 years). Sorry, computer nerd here.
