Assuming they make them for the Audi 4000 4 cyl, I'm sure they can be made to fit. If you're feeling really ambitious (if you have the proper tools) you can use a 10v Audi header with the 5th runner cut off and hole plugged. If they even exist... I modded a 10vt manifold to work on an 8v. The first 4 runners line up perfect.