should be fine. so long as the psu holds up. whenever a question like this is asked there is something that should be pointed out. if you have to ask, its because you know, if its possible, you are cutting it close. so, regardless, you will be working your psu pretty hard. is it possible? sure. it's also possible the psu will die at some point sooner than had it not been pushed so hard.
760s are 170w a piece, 30A.
even an overclocked 4670k doesnt use that much power