you should be all good for battlefield, for watch dogs a core i7-3770 is recommanded but i doubt it will make any difference your CPU is still quite fast, i'd say your current CPU will be good for max settings but a 760 will not cut it for high settings IMO...also do you know that a 280x is quite a bit faster than a 760 and comes with 1 extra gb of memory? if the prices are similar where youre at it would be a no brainer to go with th 760...but yeah your CPU is a good match for that range of GPU's...
Also make sure your powersupply is sufficient for such a GPU...