Engine build date is 60 days prior to car assembly date, and the distributor is 30 days before car assembly date, according to reference material. I think the engine may have the distributor installed while it is waiting for its car to be built, so probably 30 days prior to engine assembly date would be more accurate. Unless the distributor is installed when the car is assembled. You can get dizzy with the calculations. I will add that the dates are approximate. We can't have an assembly line shut down just because an engine has separation anxiety from its builder!