I don't know a good setting for your chip... As they are all different anyhow... I'd follow standard OC protocol and slowly raise you clock... then memory speed until it won't go any further, then bump it back a bit... If your temps are good, raise the voltage and then rinse and repeat the steps until you are satisfied or your hit the max of the card...
Personally with all my hardware I like to see what it can do for fun, then I bump it back to a medium overclock so it will hypothetically last longer... Though I haven't had anything die yet so......