Questions on installing ABS in a 4000Q

[VFChris at aol.com]

I asked this group before about putting ABS in a 4000Q.  A few people replied
it was do-able.  Get all the parts and bolt them in, was the general
consensus.

So I bought Bentley manuals for 80,90, 100-200, and 5000, just to study what
was out there.

Here is an observation I made: the ABS in the 90Q (Torsen center diff) is a
3-channel system.  But, the ABS in a  80/90 non-Q, as well as a 5000Q (non
torsen) is a 4-channel system

So, here is my question: should I use the ABS system out of a 90Q, or should
I use the four-channel (four is better than three, right?) out of a 90-non-Q?
 Or try to use the system out a 5000 Q?  Also, should I rig my system to be
defeated whenever I lock one or both differentials?  (It is my understanding
that the ABS is defeated in this way on the 5000 Quattros).  Is it true that
he ABS can't function properly with a differential (even just eh center one)
locked?

Thanks in advance for any ideas.  Please e-mail me directly, as well as by
way of this list.

Chris