Personally, I've searched numerous threads on this topic, to kind of 'prep' myself should the day I get into your current position, but this is what I've deduced on what has to be switched.
All the accessories should be fine, like A/C compressor, SLS, etc.
I believe you need the distributor, the engine and accompanying harness, I believe the transmission is slightly different with first gear ratio, so I believe you want to take the trans and the trans module as well. Not sure if those are optional or not.
You'll want the KE Jetronic control box (ECU) which is behind the carpeted panel adjacent to the passenger fender. it slides towards the seat to get it off. Big black box, can't miss it (ballpark of 24cm x 20cm x 6cm? Sort of a waffle pattern on it). Well, unless you're looking in my car where it is no longer installed due to it being broked
Maybe the idle control relay thats under the false passenger footwell too.
Aside from that, I'll leave it to the experts who neglected to post any nuances I may have missed