If your motherboard can take it and if you have a decent cooler, you should be able to overclock that FX-8300 to 4GHz with little to no voltage adjustment.
I used to have an FX-8320 running at 4GHz with some undervolt going on and it was 100% stable. That 1GHz should make quite a difference in your case, give it a try, small steps at a time though .