That’s bizzare that ECS screwed up the diffs! I think you’d be fine swapping out the n62 diffs with the m62 diffs. The 4.6 E53s shared the same diffs as the 4.4 versions and the 4.6 makes almost as much power as the b48 version of the M62. An xtra 10 or 15 HP shouldn’t blow the diff up.

The question is, will the front diff from the 4.4/6 bolt to the oil pan of the 4.8? I doubt it as they look different on RealOEM and have different part numbers. I bet Quaife makes one that’ll fit.

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Current
Original owner 2002 E53 X5 4.4i to 4.6i swap
2025 G06 X5 50e
Former
1972 Audi Fox
1986 Saab 900S
1996 BMW Z3
1998 BMW E36 M3 Sedan
2004 BMW E46 M3
2006 Audi A3 Quatro
1993 Mopar 318 Jeep Grand Cherokee
2015 V6 Jeep Grand Cherokee