An X800Pro has a chance of softmodding into a 16-pipeline card, effectively an underclocked version of the X800XT/PE. I am not sure whether or not there is a sticky for this, but remember that it is a chance. I am sure you could do the same with an X850 Pro, though I have yet to see one myself.
Edit: Short version to answer your question:
Yes, I am sure an X850Pro has as much chance of modding as an X800Pro.