Be careful. The 6300 and China released 6330 are both 95w 6core cpus. The 6350 is a 125w 6core cpu, not at all the same (architecture is, voltages and heat output are most definitely not). Many of those older am3+ boards only support upto 95w cpus, doesn't matter if they are 4,6 or 8core. As is, ASR claims the 890 GX Extreme 3 supports upto 140w cpus. With the heatsinking and max capacity of that board, a 6350 will work fine at stock, or very small OC, the 95w 6300 will be slightly worse at stock, but because of lower TDP, will actually OC much better, having more headroom thermally.
Will it work? Yes, the 6350 will work. Just not all that well. The 6300 would be superior.
According to cpu-upgrade, only the fx-4100, 6100 and 6330 are supported, but it's an old list. I'm unsure if later listing would have included the 6300 or 6350, so try at your own risk, physically it'll fit/work but if bios doesn't support the cpu, you are dead in the water.