Torsen center diff in Quattro I car?

["Wm. Josiah Erikson" <werikson@hampshire.edu>]

This is NOT an invitation to ask me why I would want to do it, and to
debate the merits of the Torsen vs. open/lockable diff systems. I'm just
curious whether it would be difficult to take the transmission from,
say, a '89 90Q (Torsen center diff, right?), and bolt it into my '87 QSW
(mechanically the same at that point as a 4KQ). Also, would a 5KTQ trans
bolt right in? (Looking ahead to possibly an MC motor).
    Thanks much,
    -Josiah