The 5000+ BE is a G2 stepping.
TC91 is correct. You can probably expect to reach 2.6 GHz without even increasing the voltage, but if you're lucky you could take it beyond 3 GHz with some tweaking. With an G1 stepping Athlon X2 4000+, I found the best performance with absolute stability on +.025 voltage increase at about 2.7 GHz.