You are looking for the Data Plate located on Left Inner Fender (engine side).
I took a picture of my ‘86 5th and from an old one (when I total out a car or scrap it, I’ve saved the tags - but not sure why).
The other picture is one from a Green 70 Plymouth Satellite I had many many years ago. Eng code is E63 (383 4-bbl HP Auto).
The code for one of my ‘77's is E44 (318 2-bbl).
The grey car picture is ELA (318 2-bbl).