Just a quick on, as someone who has had that motherboard - is there a bios for Piledriver CPU's? I'm sure when I looked I couldn't find one. Just check that out first. It's a good board and will overclock well if you have decent temps. 4ghz should be easy enough, I would even say 4.2 if you wanted to push it again (which should be doable) I had great overclocking success with that board using Phenom II chips. If the chip you have can overclock with no hitches you should be able to find a stable config for 4-4.3ghz.
Personally I wouldn't upgrade now. I would wait until another AMD platform comes out, prices are already dropping with the last high end AM3+ chip supposedly released. Overclock the nuts of the chip you have and get you performance boost for free. Invest the money in a h100i before a 8350. Thats my thoughts anyway.
Good luck with the decision. The 8350's are wonderful chips so I can understand the temptation.
Personally I wouldn't upgrade now. I would wait until another AMD platform comes out, prices are already dropping with the last high end AM3+ chip supposedly released. Overclock the nuts of the chip you have and get you performance boost for free. Invest the money in a h100i before a 8350. Thats my thoughts anyway.
Good luck with the decision. The 8350's are wonderful chips so I can understand the temptation.