The parts manual is a good source for the part number of a distributor by model and engine/trans type. If dual point the Prestolite # is given also. Like IBS-4010. Plug it into google and you can find a picture. I have autolite and prestolite service manual which will give you all the part numbers of all the individual parts to make the distributor.

Does anybody know how to decipher the date coding on a Prestolite tag? Here's data on a dozen tags from photos or actual tags.

Looks like the part number is the model year, the numbers 1-12 are the months, but the alphas A, B, and Z might be plant or assembly line codes?

I would like to see a picture of the tag. For the vintage you are showing the tag has chrysler number then IBS-4015 for your 68 as example. Date codes are 2 to 3 numbers week and year. A letter may be after the IBS number which is part of the part number. For example a IBS-4014, 4014A, 4014B are all different distributors. An IBS-4014S is the Service over the counter distributor for the 4014. It would also have a different Chrysler number.

In the Hemi 6 pack world, there were changes to distributors that had the chrysler number stay the same, but the IBS number changed. Same distributor for the same model car, but some internal change. This created the early versus late model stuff.

Attached is a picture of a 70 hemi tag.

This is the tag from the 2nd line on the list, the 1968 340 auto. The seller says the date code is 8B. I guess August 1968, plant B.

I don't see any week/year codes on this tag, and the Hemi tag does not say Prestolite at all, meaning that appears to be a tag for a Chrysler made distributor, not a Prestolite made distributor.

Another 2875 105 with same IBS-4015A, and date code 2A. AFAIK the red color is not original? I guess February 1968, plant A.

In earlier years, Prestolites did have longer date codes. This 2444 853 is said to be 1965 Dodge/Plymouth 273hp 4 barrel auto and manual trans, stamped IBS-4013, date code 38 4, I guess week 38. If the 4 stands for 38th week of 1964, that would be September 14-20 week of 1964, which does not fit with October 1 being the start of a new model year? On the other hand, it could be that Prestolite did not exactly follow the auto makers' assembly line calendar, and the date code is, indeed, 38th week of 1964 headed for the October car assembly lines of the 1965 model year. Supposedly car makers wanted the new models to be available in the fall, because that's when farmers had their cash money annual income in hand, ready to buy a new car.

Earlier years used a date code letter for year. If you look at those 68 340 tags they are much different in lettering on tag than other tags like the 4013. 38th week of 64 works for a 65 model. I am sure there are some made earlier and others later. As long as no "S" not a service distributor. I may have a 340 distributor tag. I will need to look at it. But the first 2 tags you show are unique with that embossed prestolite limited for 1968.
From some older jeep documents and such the letter code for year would have to repeat going back from the autolite days to the prestolite.

This the early 60s letter codes I believe are correct:
R = 60
S=61
T=62
U=63
V=Not used Corrected
W=64

There was no plant code. On the early ones it was month year. 5 R May 65.
Later it was 3 numbers and week year. Transition period????

So it is interesting after doing some research on the 340 distributor. It does look like it used that unique tag from the examples I seen. I would add the IBS numbers to your list as the letter code after the 4015 helps with model year too. From you list I would say:
Z=67
A=68
B=69

Also, the 4015C 3438317 is the early 1970 distributor. The later version 4018 retains the 3438317 chrysler number but has the different IBS number as I mentioned. I would believe the number in your list is a month. Why they did this for the 340 distributor, when all the other IBS around that time was in a new format with different tag logo is beyond my knowledge.

I learned something new today.

For those that are not familiar with my service, I have been supplying custom made tags for Prestolite distributors for several years.


Contact me with your specific needs.


Bill Rolik


bremotorsports@verizon.net


201-394-5533 Cell/Text


P.S. I also offer tags for single point tags as well, in the correct anodized colors for the specific unit. 4 date codes per unit per year!

Yes, I had researched those old Jeep documents also and made a calendar. Note that their 22-letter alphabet excludes the letters I, O, Q, and V. Therefore W=1964 and X=1965, etc. See chart below with the years we are discussing in orange.

So these are the year codes, not plant codes.

X = 1965
Y = 1966
Z = 1967
A = 1968
B = 1969
C = 1970

And the numbers 1 - 12 are the month codes for January - December.

Glad we had this discussion, because I learned something new too - my calendar posted above originally had an error that I was able to fix, and now the date codes on these Prestolite tags make sense.

Another error that needs to be corrected is concerning the photos I posted above on 06/17/22 of the 1968 340 auto distributor with the Prestolite tag damaged on the right side. The text says "The seller says the date code is 8B", but this cannot be true since B = 1969 and it is a 1968 distributor. I say the illegible month/year code must be either 8Z or 8A. I think I see part of a Z in the photo.

Being able to fix this error helps prove that the calendar above is correct.

The Jeep guy argue about the use of V in the Autolite days of the 20 thru 40s, but I do think the consensus is when prestolite took over no V being used. I corrected the post I made in error. Either way for the years we are focused on that is correct.

Also I check the 340 tag I had. It was a 4018 with a date 1 0. Standard Chrysler tag like Bill shows. That is 1st week of 70. This would be the late distributor. I do not think your going to find C for 70 being used. As I said, all the other dual points in the 68-69 did not use the letter code for year (except the tach drive hemi/RB sold over the counter). Still would like to know why they used that unique embossing.

Bill, Can you replicate tags that have the prestolite embossing such as this?

There has never been any demand for the earlier tags with any form of Prestolite ID on them, so I will not be offering them.


Bill Rolik