I replied to that thread, specifically on your findings and with some questions lol.
basically the problem is with getting any overclock stable over 8.1 overdrive max clocks.

Using various other means I am certain the card is good for 850/1000 but the minute I go over 900 it seems nothing works, no 3d shift. cant use rivatuner to OC memory and atitool sucks and there's nothing else.

I guess i should try 7.11 or your modded inf with 8.1 and rivatuner...