Basically, here is what made up a "Special Edition" car:
(I will generally speak about Y82/Y84's)
The items on the list with a "*" were SE cars only. Items without no "*" could be ordered separately on any Trans Am.
1. Black exterior paint
2. Gold Decals
3. Gold pin-stripping*
4. Sail Panel Decals* (77/78) (79/81 had 6" sail panel birds for SE cars, all others had 3" sail panel birds)
5. Gold headlight grilles*
6. Red nose emblem (77/78)(Gold Nose 78/81)
7. Gold Wheels/Rims
8. Gold Firebird wheel emblems* (78/81, red for 77/78)
9. Gold Firebird door emblems* (for cars with power windows)
10. Gold shifter emblem* (Automatic cars)
11. Gold horn button emblem*
12. Gold dash bezel*
13. Window molding blackout (trim around front and rear windows was painted black instead of chrome)
So, as you can see from the list above, it was all about looks. The "Special Edition" package was nothing more than a "appearance" package. It had nothing to do with power options, engine, transmission, suspension, etc., ..... just looks. This was just off the top of my head, I may come back and revise this if I remember anything else.