Give it go and see.
To get my 6800GT scores I did overclock both clocks (450/1250), your ram and will overclock higher if:
1) Using Rivatuner you disable to clock test
2) Use some ramsinks in them to draw heat away from them
3) Use a 2nd fan to blow cooler air over them.
4) Remove any PCI covers on your case to allow the hot air to escape quicker.
Hope this helps.
Cheers
Mav
