Any advice ihave got a w126 280 s and intend to put a w124 300d engine in ,however would prefer a 5 cylinder sd engine from an s class diesel exclusive to us market does anyone know where i could source one my cars w124 300td ,w126 280s , w124 200e also anyone ever change a rear diff out of a w126 280 s and where i could source a replacement diff are e class diffs the same as s class quality etc