Not much of a Gain for the Cost still less than 10fps when similar overclocks are achieved. Considering that the chip under load sucks up 330 Watts you would need a 650 Watt power supply or larger depending on your GPU, you also need Liquid Cooling for decent overclocks as it runs very hot. Most motherboards wont get a good overclock or even run that chip as it's a 220W so a 8+2 VRM is a must.
What you will notice is that a I5 4460 "$168" in Gaming across many titles surpasses anything AMD has to offer. A FX-9590 "$217" ,FX-8350 "$165" and FX-6300 "$94" are very close to each other and a I5-4960K "$219" and up are Considerably better. This will also show you that a I5 4690K and I7 4790K "$319" are neck in neck when gaming is concerned. The only reason to consider a I7 is if your planning on Running 4K Resolution and Multiple GPU's or Heavy Rendering. For a Single GPU setup the 4690K is as good as it gets.
That board you have is much better suited for the 6300 than the 8350. The vrm's are too weak for the 8 core. You would end up with worse performance because dollars to donuts the 8350 would be throttled.