you can flash any reference 4870 with it. Stock clock speed is 800MHZ though, so you need to make sure your card can handle it (though most should).
Or you could use the Radeon BIOS editor and put the core speed to 750MHZ (standard 4870)
in CCC, the upper clock limit is 990MHZ with this BIOS
You can break 20k in 3dmark06 with a 4ghz quad and a highly overclocked gtx260..... I'm quite impressed with that card, I hope the die shrink is even better.