entertaining a 20vt conversion

[agaidos at got.net]

 Someone locally is selling their totaled '91 200 20vt. I am, at the least,
planning on buying some parts off it for my wife's car. However, I've since
started contemplating the pros and cons of transplanting a 20vt motor into
my '85 urq. Realizing I would be working on one of the rarest Audis in the US
and may cause irreversable changes to the car hasn't gone without thought.
 Having said that I am interested in opinions concerning both technical issues
like wiring in the newer, more complicated engine management system as well as
purest opinions regarding modifications to an '85 urq. I think from a
mechanical aspect the motor bolts right in and that the big headache would be
getting it to work electrically.
Anton