Rear differential

[Dave Binkley <dbinkley@argotech.com>]

What is involved in upgrading a stock Mark 1 rear end (2.88 ratio) to
positraction/limited slip?  I don't want to change the gear ratio.  Are
the parts available new or do you have to scrounge up used parts from
vehicles that had Dana 44 rear ends with positraction?  Can anyone
recommend a shop in the Bay Area (Northern CA) area that you would trust
to do the work?

Thanks,

Dave