Thanks everyone. These date codes are what I expected. It appears that wheels, dated about 2 - 6 weeks before the car build date can be considered “ideal”; however, as we have learned, anything is possible.
After I posted the question, I found a similar discussion from October 2007. From that discussion JohnZ noted that the Kelsey-Hayes rims came by the thousands stacked herringboned style in rail cars. The assembly plant was not concerned about pulling wheels in common date coded lots, but rather to keep them grouped in correct wheel contours and sizes.
Learning how material was shipped to the assembly plant: lot sizes, dunnage packaging, frequency of shipments, etc., gives us clues about how variations in date codes among the components are often found.