the simple answer is yes it will for sure work but for how long is the question it will run the card but overtime it will cause the psu to die faster
in the long run the 1080 does not use much more power than the 760 but the issue is that the psu is not made for this kind of load meaning that it is not 100% safe to run the card i mean a 150$ card like the 950 (pretend it uses the same power for now
) i would take that risk but one a 700$ 1080 i would spend 50$ for a psu to ensure the card's safety along with the rest of the system
http://www.amazon.com/dp/B00DZ6R9GE/ref=twister_B00MXYPPRY?_encoding=UTF8&psc=1
i would get the 700w model of this psu as it is cheap and if not heavily overclocking good for you
EDIT: get the 600w model if it is cheaper but for me it seems for some reason the 700w is cheaper