RA062123

I keep seeing people talk about different rear end ratio's and swaps but has anyone ever actually done it? I recently blew up my differential and was looking for a replacement and thought 3.07 is a tad tall... From what I've seen early e300 diesels have 3.4~ right?? That would be perfect. So if anyone has actually done it with results and steps on doing it that's be great! Who could I get to flash the tcu? I've also thought about completely swapping over to the amg transmission and differential and just plugging in the amg tcu, do you think that's ever been done and has any merit? (More than likely I won't because of 1. Money 2. At that point I should've gotten an e55 or c32 amg)