You can do that with E30's as well taking the E46 6spd and bolting it to an also swapped m50, m52, s50, or s52.

I think with the E53 the problem you run into is not with the physical part of it but the electronic. I'm just guessing on that, but if I ever get an e39 540i/6 that was wrecked and a non-lci E53 I'd love to try the swap... hell maybe the trans would even bolt to an N62...?

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