My thoughts? Pointless exercise if you're after performance. The only reason I'd do it would be if I really enjoyed modding that sort of stuff and had felt a need to just to see what it can do.
When it comes down to it, you'll be adding proper WC parts, and to get any better performance you'll be changing the rad first, then probably tubing, followed by maybe adding a res. After all that, there have been some people who said their pumps failed on larger modded loops, so you'll need to change that too. So basically you'll have a custom WC loop with nothing left except maybe the fan from the Corsair (which isn't very good anyway).
If it's more performance you need, look at the Thermalright Venomous X or Noctua NH-D14. If you must have water, OcUK have some kits on their site now, should give you an idea of what you need.