Alpila B7 powerplant and drivetrain in a e60?
 

Ive got a 2004 545i that requires an engine overhaul, so rather than rebuilding what shes got, Ive opted to go a different route. I picked up a 2007 Alpina B7 with 90k miles to donate the engine and trans. Im wondering if anyone has done this swap before and if so what to avoid, what to look out for etc. Thanks for the help, and input.

does that have the updated gear shift lever or the previous one?

If it's the new one a few modules need moving over as the gearbox won't go into D because the engine ECU is sending different signals and the two don't work together

I'm going to guess that the ECU is going to need to go with the engine. I'm not sure how you are going to code the ECU to your car.

Is the Alpina B7 motor a V12 or V8?

The B7 motor from that time should be the same motor for the B5 at that time the (545i engine but supercharged) if anything look up alpina b5 stuff and see if its a straightforward swap as it seems to just use the regular zf automatic transmission