Sorry to be so late to the party on this, but just wanted to add a suggestion for acquiring 3-pipe heatsinks. Search for "6970" cards listings as "parts only" and look for heatsinks in the pictures. That tends to find the best price. I just picked up two more in the same way, so now all of my 27" machines can have one. I paid under $50 in each case. Make an offer and suggest they keep the 6970 and re-list it. Here is the listing for the ones I just bought, and the seller still has one left in case someone is looking:You're right,
It's 2 heatpipe but it's still MXM-B. I can't find any 3 heatpipe MXM-B heatsinks for sale. They still have cards attached to them and want obscene amounts of money for what is basically hot garbage. A 2 pipe MXM-B heatstink is still better than an MXM-A heatsink as there are components that need to be covered for cooling.

AMD Radeon HD 6970M 1GB Video Graphics Card For Parts Not Working | eBay
Condition is For parts or not working.
Even though I offered to let him keep the cards, he sent them, so now I have two bad 6970M cards to dispose of. Not sure if there is any market for them, especially not knowing their history, but the heatsinks (which I'm keeping) are top notch. If anyone here wants a bad 6970M card (or two), they can have them for the cost of postage. Just PM me.