Btw , the FX-8320 stock fan(heatsink) is from coolermaster company , it's awesome for temps but it's very load since it can reach +5000 RPM
you can overclock the FX-8320 using the stock cooler .
am using the FX-8350 @ 4.2 GHz with it stock fan , the max load temps are awesome , max 60 C avg 52 C
idle temps : Max 30 C Avg 25 C