Last I heard, Andrewtech was looking into what was required for the swap. I dont think they, or anyone else has done it yet, though. From what I remember you'll need both the drive and driven gears assuming theyll actually fit on the shafts of an 04-06 transmission. If I remember the prices posted on NASIOC right, youre looking at close to $2000 (including labor) to get this done, which honestly, isnt bad in the world of Subaru transmissions.