e82 135i n54:
http://www.realoem.com/bmw/en/showpa...diagId=23_0926
e82 135i n55:
http://www.realoem.com/bmw/en/showpa...diagId=23_1121
e82 1M n54:
http://www.realoem.com/bmw/en/showpa...diagId=23_1121
If you look at the propshaft lengths for N55 135i vs N54 135i they are different even though they are using the same differential.