OK....another decoding question.......

AB was engine in 65. Not in 64. 64 Barracuda's were a mid year release. (Apr 1 1964)
True that. The online vin decoder the op is using is 62-65 and they don't make that distinction. It's confusing to people without experience in decoding early Barracuda tags as the op expected to see engine numbers under the AB.