FINALLY GOT IT BACK!

It could be a simple thing as the supply on the assembly line ran low / out and they just keep the line going with intentions of correcting at a later time, or like stated previously early build as opposed to late build. My car has a build date of Dec 02 70. When I painted my duster and re-striped it I included the 340 callout cause at the time I preferred it. I believe if that's the way the car came from the factory then it's either correct for that car, or a boo boo.