Superseded Part Numbers


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Feb 24, 2021
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Good Evening All
Not sure where to post this, so we'll start here.
Is there any web site that deals with Mopar superseded part numbers?
I thought maybe 'My Mopar' would , but to no avail.
My "65 parts book is a great starting place, but as part numbers where changed, unless you find some 55+ year old NOS parts (usually $$), you really don't know what other part numbers will work.
There use to be a defunct Chrysler dealer ship not far from me (Funkhouser Motors) that would keep up on all the superseded numbers but, alas, when Paul passed all that material was dumpstered.
Thanks to all who respond
Superseded part numbers usually indicate a change, sometimes it will work sometimes it will not.
Part numbers didn't change each year just to change.

I worked at Mopar for many years. The rules of supercedence in general is that if older part "A" is superceded to newer part "B", then "B" will work in the older application, but not the other way around. This was used to minimize inventory, and often because the supplier refused to produce the old part any longer. A prime example is the use of the "shorty" oil filters introduced in 1973 for belt clearance on B engine vehicles.
The supercedance information was available to dealers on the parts ordering system, but the data was removed when the newer part was finally discontinued.
Mopar did publish an "OSI" manual - obsolete, superceded, interchange - periodicaly. They are out there, I have at least one copy, it is the size of a regular parts book, numbers only! It would be a huge task for put all of them online.
As a workaround, the reproduction suppliers usually do a decent job of checking application on their parts, if a 68 part works on a 65, for example.
In my experience there are at least three older Chrysler Parts suppliers that have that kind of information if you have the original part number to begin with. Marty at Arizona Parts can usually help who is also a member on this site, Deception Pass Motor parts and as well. Marty usually has the best prices, then Deception Pass and then AMS in my experience. Prices also depend a lot on the market demand for a certain part and usually parts suppliers know which ones fit that category.
The books were called COS (Cancelled Obsolete Superseded)

I still have some of them I got from dealerships as they came out periodically.

I have some from the 1930s on up.

Sometimes the list is amazing as a number may go through a huge number of changes

see example pictured

U means superseded to

NS1 NS2 etc. means cancelled (discontinued, not serviced)

The parts men would sometimes just say NFG (no ******* good) instead of NS1

Sometimes the numbers would change because:

A different vendor was making the part

There was a change in the part

Note: numbers starting with C3940 are all recall parts

for example:


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