That's the phenom without L3 cache rite? If so, then yes, i think it should make a decent upgrade, especially if you clock the FX up proportionately, to say around 4.5GHz. But don't expect earth shattering improvements
As someone suggested before, sell off your old chip to make your upgrade cheaper. And I think you're educated enough to know to check your mobo's updated manual for CPU compatibility with the latest FX chips, and to flash your mobo with the latest BIOS too
All the best