What plant made yours? The Hamtramck/dodge Main started the Ser. no at 500,001 for A body Valiant/Dart models, for some reason, or so the published sources say (For example, "Each Plant consecutively numbers all vehicles beginning at 100001, regardless of car make or model, except Hamtramck built Valiant and Dart models which begin at 500001." at https://www.geocities.ws/MotorCity/Speedway/9048/vin.html ). Although the Barracuda was made at several other plants that did not use the 500,001 as first one (st. louis for example and LA). A 1966 vin with 499,*** is another MoPar mystery if it was a BP29D62XXXXXX.... almost like they were just making cars and not worrying about a bunch of us trying to make sense of it 60 years later.