Is there a reason why? You'd almost certainly be better spending the money (£30 for the aio bracket and £60-120 for the 240mm+ AIO) on a newer card.
Even the best water cooled overclock won't get you more than say 10% more performance.
980ti is still a good card. But its beaten by the 1070 & 2060 so I wouldn't spend too much money on it.
Though if its less performance, and more for the hobby, enjoyment of modding then go right ahead sir! I used to run a NZXT G10 aio bracket with a standard aio and it was good fun for sure
Just don't think I'd do it again. Minimal performance gains (couple %) for over £100. It would have been better to buy the card/cpu up.