eVGA 8800 GTX with a modded AC3 bios

[Solarfall]

so yeah use it for shader clock increase but do you reckon the same timings will work on an XFX or is it better to just have a play around with them one setting at a time and test that way?

i would recommend to play it safe, increase mhz with tiny steps and test that card works properly, play some game or run benchmarks like 3dmark.
if the card seems to run like it should and does not cause artifacting, just increase it little bit more until you find your cards max setting, thats pretty much what i allways do when i overclock my video card, ram or cpu.