It should run very well.
http://www.pcgamer.com/2013/10/08/watch-dogs-system-requirements-announced-specify-64-bit-os-and-minimum-6-gb-of-ram/
Look at the Reccomended specs. Either a fx8350 or a i7 3770. Knowing, that you have a 4770k, you should max out everything. And the RAM is 2x as much as needed and the graphics card is even better. So, yeah, In my oppinion, you should play on ultra no problems.
Good Luck