rear differential movement / clunk

["Grant Lenahan" <glenahan@notes.cc.bellcore.com>]

re: excess movement and "clunking" from rear diff of 1991 90q20v

Well, this weekend I replaced the 3 rear diff bushings to cure
movement in my 1991 90q20v.  This appeared to be a no-
brainer.  Several previous cars had the same malady, and
the bushings corrected it completely.  I could move the diff by
hand from under the car.

Bad news: new bushings, same old clunk (when shifting, starting out,
etc).  When "bucking the car" against the handbrake, the diff and 
driveshaft could be seen to twist substantially.

Any of you raw-knuckled folks run into this?  What am I missing?

Grant