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

Maybe it's because you have an early expected build date and it is the first year for a Barracuda. A Valiant tag search decoder might come in handy here. All the later tags I have seen would have numbers under the Capital AB and sometimes the C if you had a performance package car or formula s car. The online tag decoders support what you are saying as typically they would have the engine packages under the AB. The top line having nothing is normal. Luckily you have moderators like Mike with good information you can't get off a typical online search.
AB was engine in 65. Not in 64. 64 Barracuda's were a mid year release. (Apr 1 1964)