I guess you are speaking of the 124 upgrade. I have done this on a few cars with VERY good results. I use the alternator from a E320. It is a 90A Bosch unit.
You have to get the alternator and the pulley to make it work. Also, you will have to cut the ends off of the spade connector and install a ring terminal. Do this with solder-on ends to ensure a good connection.
You will notice on your vehicle, you will have 3 connectors in the plug on the rear of the alternator. Put a small ring on the small wire and install it to the small stud on the rear of the alternator.
Put both of the large wires together and install a large solder type ring on them. Install it on the large stud on the rear of the alternator.
ASE CERTIFIED MASTER AUTO TECHNICIAN
MERCEDES SPECIALIST 11 YRS