Could you Overclock this?

Hi! My friend asked me about overclocking his AMD PHENOM X4 965 BE and I said its possible to  overclock it over 4GHz. But is it true? .__. (He use a Cooler Master V6 GT as his HSC)

open up a CPU z, and check the revision, if its a C3 then there is a high chance he can get to 4Ghz, and it is thermally reasonable on that heatsink as well