Bolt holes will line up. Steering box shouldn't be a problem but if it is, add a washer on each motor mount to raise the pipes up a bit. Your starter's heat shield will get in the way.

The #1 thing you'll hate is the geometry on an e53 vs an e39 let's say, is different after the bell housing. The e53 collrctors drop way down at a sharp angle compared to the sedans so you'll have to deal with that.

Just as well, the o2 sensor will/might need to be repositioned or your DME will rrad wrong and give you bad a/f ratios.

Good luck.

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'03 4.6is (the wife' s ride)