Date codes, we hear about them all the time, some folks doing the 100% perfect concours restoration are quite serious about having the correctly date coded part. Some folks just like to "get close", others do not care at all. There are also those that need to know the date codes so they can gouge top dollar from the serious restorer who just happens to need their part. Once you start looking for date codes it can be kind of fun, and it sure beats grocery shopping or knitting.

Lets start with a general overview. Lots of the parts used on our cars have date codes, a major reason for this is tracking items in the event of a recall, if a part suddenly had a lot of failures it would be subject to a recall and usually within a specific date range. Having the date on the parts made them easy to check. There are several different types of date coding. There is Month / Year, Day / Year, Month / Day / Year, 10,000 day calendar and so on.

I will list items here as I find them or as folks send in clear photos and a brief description, so lets get started.

First, we have a muffler for a Challenger T/A, the date code on this one is in easy month / year format. 3 is the 3rd month, 79 is for 1979, so this was made in March of 1979. Why 1979? Because this is a NOS replacement muffler.

Here is a radiator, the date codes for these are on the passenger side steel frame and the number is visible from the engine side. These are in Day / Year format, our first one shows 0379 — 037 is the 37th day, and 9 is the year, so this one was made the 37th day of 1969.

This next one shows 087-0, same format, it is for the 87th day of 1970.

Seatbelts are in Year / Quarter format, so this one is from the 3rd quarter of 1969.

Next up we have two u-joint retainer caps, these are in Month / Day / Year format. Note that the dates differ even though these came from the same car. The one on top is from October 7th 1969 and the one on the bottom is from December 8th 1969.

Our next one is a rear valance from a Challenger, these are in Month / Day / Year format, so 3 18 70 is March 18th, 1970.

Bumper jacks are date coded as well, here are two examples of dates stamped in the jack body, one says 9C and the other is 0M;

The number is the last digit of the year, so 9 = 1969 and 0 = 1970 while each letter is for a month of the year;
A - January     B - February     C - March     D - April     E - May     F - June
G - July     H - August     J - September     K - October    L - November     M - December
- Note that the letter "I" is not used.

So the two jacks pictured above are date coded March of 1969 and December of 1970 respectively.

Some jacks have the date code on the rivet head instead of the body as shown here, this one says 9J for September of 1969;