Transmission identification a833

Based on the date code of 4521 it was the 4 thousand 2 hundred 12th transmission built at New Process Gear in Syracuse NY in December of 1973. This would have been installed in 1974 A-body. Don’t discount the fact if the tail shaft case doesn’t match the main case because someone may have rebuilt it from parts. I’m currently rebuilding my 64 4-speed transmission using internal parts and tail shaft parts from a 68.