[Schonyenko2]

On a challerger the vin# is embossed into the dash pad. It does not come out unless there's a new process that I am unaware of. That can cause a lot of head aches if you use a good dash from another car.
That's also correct about it needing to be a 383 or bigger to be an R/T.
If it's a 440, 440 6pac, or hemi with a 4 speed, it most likley is a dana. Any of the above could be an 8.3/4 with an auto. This can be misleading as different combos could be ordered although a 383 727 dana was possible, a 440 6 pac 4spd 8 3/4 was not.
Ebody mopars are cool. Just remember mopar parts are pretty pricey.
Just in passing, the new goodmark challenger fenders are very nice.