If I understand correctly the build sheet will have a time that it was on the line on it, if you have that. It would interesting to know the engine build date and time on the sheet. MY car was a 407 car and is believed to been on the line on 403, a friends is a 403 car and it was done in March, door sticker is 03/70, my door sticker had already been removed when I got my car. Point is they had been running a head of schedule a week or so before your SPD.