TB303, you look to have pretty much reached the OC limits or your card. There is much more to be gained by upping your FSB anyway. 450x8 on your CPU would give a nice gain over 400x9. Messing with the GPU OC any more will only gain you a % or two in terms of performance and will really be straining you card.
Just my opinion
EDIT: If you still want to get more out of your card, try dropping the core a little (700mhz ish) and raising the memory OC.