Hi all starting my new project

[Immyrs]

HI everyone in the last 12 years I've owned a e61 m5 touring and used it for everything I love this car and could never sell it
I've acquired a heavily damaged m140i and will be doing a full engine transplant.
I've heard from a few people that I'll be needing a full standalone ecu how will that work is it plug in play with all the e61 interior stuff
Also I won't be using the m140i diff
I'll be using the m5 diff and rear axle
If anyone could help that would be great