E550 engine swap with a M113K from a E55 has it been done
What you need most importantly is the ECU, TCU, key, ignition, gear shift knob and steering column module from the same car, they're VIN tied to each other. I think the TCU isn't and maybe the gear shifter isn't either but the ECU, ignition and key and definitely needed.
It's been done before but why do you wanna do this, honestly it's much much much much easier to sell your car and get an E55. They're SOOOOO cheap now over there so what's the point. You'll just waste time and money.




