I have on my 2.7 conversion a somewhat unique system. It is CIS but it is using a audi 80/rabbit airbox, see pic
http://www.theidiotsvillage.com/misc/car_p.../pict_pg_5.html
I was told that I would benifit HP wise from better breathing. And that I should cut some circular holes in the bottom of the airbox, as well as enlargening the tubing that leads to the thorttle body. As you can see in the pic, the airbox opening is just above and below the large breather oil tube, and the tubing to the throtle body gets smaller in diameter closer it gets. Anyhow before I start messing with a very smooth running CIS I thought I would ask opinions. Ferg