Gents the good 1080Tis (Xtreme, FTW3, Lightning) dont need watercooling. All of them are clocked at 2021, most with great coolers (eg Xtreme) will do 2063 on air, and you cannot get more than 2100 under water.. Is more cost efficient to replace the thermal paste with liquid metal and hit 2080Mhz and replace all VRAM silicon pads with Thermal Grizzly Pad 8 than watercool those cards.
Make sure you have good PSU because they need 330W+ above 2000mhz. Dont look at those stupid sub 300W reviews at 1850 clock...
Also you will find yourselves wandering if there is need to overclock for just a pitiful few FPS. Especially 2560x1440 & 3440x1440 there is no game to beat it....
Assuming you don't activate HDR.