I hate to pop your bubble but there is not a great deal of stuff, especially between the engines, that is transferable.

mass meter NO
IAC NO
Fuel Pump YES
pump relay NO
OD relay NO
Control units NO

You're going to find that most of the stuff that will swap from one to the other will be body parts an interior stuff. If one has nicer wheels and tires than the other you might want to swap those out, grab the rear view mirror, maybe one or two of the grab handles so you can put one on the driver's side as well. Take a look at the interior plastic stuff like maps pockets, trim rings, the panels that go over your knees (under the glove box), horns probably interchange.

Your other problem here is that you are going the wrong way, you are trying to see if there is anything worth saving off of the '84 to put on the '89. You need to be doing it the other way around. I just did this on my daughter's 85, had a customers car that was totaled and going to the boneyard and she gave me the green light to swap out anything I felt like I needed. The daughter got new wheels, tires, hub caps, cloth interior, later styly side view mirrors, newer fuel pump/filter assembly, map pockets, visors, bumpers, mouldings to go with the bumper, and tail lamp assemblies. I gave a good look under the hood but there was just nothing that crosses over and my kid is running a B230 whereas you've got a B23 in that '84 (even less compatability). Mad dog that I am I even gave serious conderation to doing a complete engine, trans, injection, ignition swap between the two but it just was not doable in the time frame.

Hope I did not pop your bubble too hard there just is little to no commonality under the hood on those two cars.

mark