When a body in white was assembled, what specific pieces or panels would be different from car to car?

For example a coupe would require different parts than a HT or four door.

An A/C car would have a different fire wall than a non A/C car.

Is there a different floor pan between console and column shift automatic cars?

Is there a different floor pan between floor shifted manual cars and console automatics?

Is one floor pan used for all cars and the specific holes cut as needed somewhere along the line?

What about B body tail panels? Are all 69 Belevedere and Coronet tail panels the same for coupes, hard tops and four doors across all the models?

Any other parts or panels I've forgotten?

Thanks!

Hello this is Don we talked in detail about some things in MN.Still gathering my St Louis info at this time.On this topic all 2dr and 4dr B body floors are the same (uncut automatic floor shift hump) ,add mounts for buckets,console,buddy seat or cut for floor shift hump. All 2dr 4dr firewalls are the same,auto cars will show 4spd dimples/location for clutch pedal bracket.On a AC car you will see dimples/locations for the non air punch outs.A non air car firewall will show dimples/location of AC heater box drains ,water valve ,ect.Firewall might have been punched/cut to needs after body was assembled .Punch/cut floors,firewall,outer body to fit needs,options,trim level, in metal/trim shop before paint or assembly.This is when I believe our St Louis fender tags were punched also BEFORE paint!