Been there, done that:
http://www.peachparts.com/shopforum/showthread.php?t=53236
I have a 150A alternator in my 300D and E500 right now. Complete bolt-in after you swap the pulley, re-clock the alternator body if required, and install larger cable to the battery. Donor cars are late (1996-up) M119, M120, and M113 for the 143A and 150A.
DO NOT have an alternator shop re-wind your stock alternator for more output!!!
