Need some help decoding 833 PLEASE...

I rushed and bought this 833, not knowing VIN # and what it came out of, he just said it came out of an A-body. Iam installing it into a 69Dart.
Thank you for any input.

Bearing retainer- C94796
Tailshaft- C99126-1
Transmission- 4B2973980? not sure with the 0
PP833 4578
C99129 L

Again thanks for any input, Ive searched here and get more confused:???: