Should be enough, but you might run into power supply limitations if you try to overclock.
FX8320 is ~125-150w at stock, and reference GTX960 has a 120w TDP. The rest of your system probably adds up to 50w or less, whouch would put you at ~320w at full tilt - which is a nice, safe margin for a high quality 460w PSU.
However, if your power supply is very old and/or of a crappy brand, you might have issues.