Someone Somewhere said:
660 has a TDP of 140W, so 140+140+84 (CPU) = 364W. Add some for MB, HDD, SSD, fans etc. and you should still be fine, especially given that's a very very good PSU.
You should be fine, though don't OC too far.
Oh, and you could probably run your current build on a 450W+ PSU.
thanks im really gettin worried to change my PSU. i bought it last month and dont want to change it just for the sake of +100watts on 750watts PSU. thanks