Here is how the cowl tag decodes:
Decode for body number: 120222
09A = Built the First week of September.
69-12437 = Coupe.
NOR = Built in Norwood Ohio.
711 = Standard Black Bucket Seats.
57-57 = Car Color is Fathom Green
X66 = SS396 without style trim
If the cowl tag is real, then the 10 bolt axle is not original. Can you get the production code from the 4-speed? Look here for more info: http://www.camaros.org/numbers.shtml#TransmissionNumbers
You should also post the vin# so we can make sure the tags have not been swapped.