So this is pre build stage. Still just trying to get everything planned out. I love my Audi's and I have a few. My plan is to take the 2.7t out of my 2000 A6 and build it to stage 3 and put it in my 1998 2.8 A4. I am aware of the challenges with the ecu and wiring and have a shop to help me sort that out. I'm interested in what else is changeable. I plan to take the bigger brakes and tranny, but are things like the front and rear diff able to go back and forth? My big advantage is I do have a whole machine shop St my disposal so small differences could be overcome. Any info is appreciated I am just trying to get my plan sorted out so that come spring time I know what I'm doing. Thanks!