I have a pair of Sapphire 2GB 6950s with the BIOS switch that allows you to easily switch between the 6950 and 6970 shaders. Both cards are currently running unlocked, in crossfire, at 6950 clock speeds without a single problem. The BIOS switch doesn't change the clocks, but both cards should run 6970 clocks fine via software. I ran one card at 6970 speeds flawlessly before I bought the other, but when I had them in crossfire, I kept the clocks at stock since I had no need for the extra speed. One is the Dirt3 edition, and the other is the non-Dirt3 edition, but they are essentially identical.
$205 + shipping each via paypal. I am located in Austin, TX if you're local. I have lots of feedback on various forums and eBay, so don't hesitate to ask for some if you'd like some reassurance. I can provide pictures, but they will be taken with the cards in my PC since I'm still using them.
EDIT: Both have been sold.
Edited by DarkScorpion, 16 April 2012 - 03:23 PM.