trying to learn basic and more about it.

even hough I had 99A6 with 2.8l I bought haynes manual on A4 & Passat.
so all the 2.8L 30v engines are same on all models right? is there any difference in ECM setup or all same?
and also engine bay area what are the difference between 27t, 2.8, 4.2 do all have same engine mount position etc?

I know more on chevy and nissan, but when it comes to audi no clue. I driven vw once when I was 18 (my first car was rabbit...) that's like 18 years ago..

I'm gonna try reading that whole manual and see if I can get info I need, I just have to know what I'm driving.. always have tis thing that I tear a part and learn what I'm playing with. toys or cars.