I don't think this Audi Coupe was ever available to the US market. The only Audi Coupe Quattro available in the states came with a MC1 engine (turbo) .

The link you have there , looks to be , from the numbers, to be Euro motors only.

Jeff ,
Since you have an Audi Manual , and I considered non biased in this issue ,do you mind if I ask you to check or reaffirm some references to the Audi manual ?

If yes thank you in advance.

There is exhaust header difference. The illustration begins on page 26.4 of the Audi Manual. The first illustration being used on Quattro models. The second illustration is on page 26.6 ,this shows the Coupe GT exhaust manifold .