You'll probably have to remove the fan, which may cause problems. I'd try removing the fan without adding watercooling first and see what it does to your system. If it causes problems outside of the processor temp, you may want to reconsider.
_________________________
Cheers! :-)
- JediJoker

Current:
- "ProBook:" 15.4" MacBook Pro Core 2 Duo 2.33 GHz
- Mac Classic II
- Old PowerBook

Moved On:
- "The Book of Power:" 12.1" PowerBook G4 Aluminum 1.33 GHz
- Purple iMac