3 series posi carriers are ALWAYS of interest. I have a couple 2 series posi carriers, as I want to go a little higher with my rear gears, from 3.07 open to 2.73 posi (using a carrier that had 2.73 open). I ended up buying a 4 series posi case for the internals. I opened it up and everything inside looked ok, so it was cleaned, re-lubed and reassembled into the 2 series carrier. I've only gotten as far as putting the 2.73 ring on it, but am yet to reinstall it in the housing that once had the 2.73 open in it.