there are a few people that know some of the things you are asking but there is only one person (rudy) that really knows everything that needs to be done in this swap, (this is his profession) ,, try to do it all your self when you get stuck, send the car to rudy and pay him to fix it correctly, I am niot tring saying you can't do it ,,well yes i guess i am , I have made over 30 engine swaps in my lifetime and some were easy,( just hook up the electronics) and go but when it comes to Mercedes,VW, & Audi,, I leave it to those that have the 10 to $20,000.00 computer system to make them work the way the factory said they would. don't rethink it do it ,,i just hope you don't have both cars down for more than a few years. (NOTE) you have to use the tranny with the rear it came with, example srt tranny u must use the srt rear,,use the limited tranny you must use the limited rear . maybe this will help.
https://www.crossfireforum.org/forum...gear-work.html