I am now a new inductee to this club. I did this mod to my reference Powercolor 7950 Boost State. When I took off the shroud, the VRMs already had heatsinks (at least I'm pretty sure they were VRMs and that those were heatsinks) on them and there was no additional cooling to note on the shroud itself as the actual GPU heatsink only covered the GPU itself.
As it is now, my temps under 100% load at 1180 MHz/1400 MHz top out at about 61C, with my VRMs reaching around the same temperature (low 60s). I'm very happy as this mod has eliminated the headache I got every time that reference fan span up, and it gives me peace of mind knowing my card doesn't reach 95C in Metro Last Light.
I purchased the bracket/shim/92mm fan from a user here at OCN for $20, and an Antec Kuhler 620 for $30 on another forum, so I'm incredibly happy that $50 and 45 minutes of struggling with a shim gave me these results.
As far as the installation itself went, I used Arctic Silver thermal compound on both sides of the shim, positioned my Kuhler and bracket overtop, and got someone to hold everything in place while I mounted the screws/nuts. The first seating resulted in the shim being moved somewhat off of the GPU, leading to a computer crash during a Heaven run, so I just loosened the nuts slightly and moved the shim back into place with a screwdriver head. All in all not very difficult, but I could imagine it being a bit of a pain doing it single-handedly thanks to that copper shim. My advice to you is to just get everything mounted and not worry about whether or not something moved around (ie the shim) during installation, and to just shift them back into place the same way I did.
Some pictures:Edited by billyevans - 6/1/13 at 11:40am