4ksQ Rear Differentials - Question

[Brad Odegard <fosgate@skypoint.com>]

Quattro gurus:

As rally master for the Ojibwe Forests PRO Rally.. I end up running lead
car in the Q.  Turns out I took a large rock on a stage and broke one of 
the side arms on the front of the rear diff that mounts it to the
subframe.

I've got the diff out and it looks repairable with a good aluminum
welder.
The question I have is in regard to the two different diffs put in to
the 
84-87 4kq's.  The two models are the UR and the AEC, the UR is a single 
casting including all mounting points.  The AEC has seperate bolt on
mounts
for both sides and the rear bushing.  Now there has been much written
about
the fact that the 85-87 4k's had a different drive ration compared to
the 
84.  In some quick experiments with the several diffs we have at the
shop,
it appears that they all perform identically in regards to the ratio
between
input and output ratios.  

So what I'm looking for is if anyone has some deeper knowledge in this 
regard.  It appears to me that I can freely exchange the UR and the AEC
diffs with the only consequence being the different diff lock actuator 
mechinisms.  Phil? Huw? anyone have definitive knowledge?

thanks, Brad
--
"Caution:  Vehicle may crash or explode for no apparent reason"
--
Brad Odegard       -           KB0YAV        -         95 Eclipse GSX
mailto:fosgate@skypoint.com                      84 Audi 4000 Quattro
http://www.skypoint.com/~fosgate/
6680 Lucia Lane #15     Fridley, MN 55432-4641     Snailmail