Sorry to link to another forum but I feel that it is relevant to this person's post. I saw this on the work logs on the Pheaton forums at this URL:
http://www.pheatonforums.com/phpBB2/viewtopic.php?t=446 that may be relevant to what you are doing. Hope this gives you some ideas. The part where he discusses making a water block out of a Swiftech MCX462 heat sink is on the second page towards the bottom.