Resto-Nerd What is a True OEM Reproduction?

340 Heat Shield Markings and why I didn't mark my parts

Rich Stuedemann

9/8/20243 min read

I didn't choose my company name randomly. I have the tendency to "nerd"-out on things and doing research on these 340 hp heat shield gaskets is no exception. I wanted to share the knowledge I have from being a Mopar engineer and research on original OEM and Mopar P-part markings. Part of my decisions I made on my parts had to do with the value of the part markings and my knowledge of licensing a product.

Here is what I found on the part identification

  1. The markings on the parts

    1. All original production parts have a McCord part number - McCord is now owned by a holding company but do not make these anymore.

    2. The aftermarket parts or "P" parts I believe do not have the McCord number because they would have to license the use of the "Mc" number. McCord did this, I believe to identify them as a supplier. In my time with Chrysler/Mopar, there is a specification for traceability & Part identification that has to be added to production parts. Also, I believe that since a part number itself is not itself Intellectual Property (IP) adding the "Mc" makes it defendable as IP.

    3. Chrysler at some point starting in 1962 till? transitioned from the DCPD stamp to the Pentastar. DCPD stood for Dodge Chrysler Plymouth Desoto. The 1968-1970 parts should be a pentastar.

    4. The parts also included the production part number. The aftermarket licensed parts have this on the part but on the box is is designated as a P-part = P + OEM number.

Click on images to magnify

P-Parts, are they different than OEM parts?

See copy below from any Mopar Performance parts catalog or go online to Mopar and view the P-part catalog.

P-Parts are not service parts nor are they original equipment. As stated in parentheses " parts not originally supplied on the vehicle from factory" . The best example I can give is the famous Mopar purple shaft cams. Some of the cam profiles are exactly like the production spec'd cams but they are not service parts. Some may be produced by OEM suppliers but not necessarily. They are more comparable to day 2 modifications that you could go to your Mopar dealer and purchase. In the early 70's they were marketed under Direct Connection and are now returning to that marketing again. So the P-part heat shields being sold as NOS (New Old Stock) are technically not NOS.

So, my conclusion is that technically speaking, for a reproduction 340 heat shield (or 273/318, etc.) to be OEM correct, it should include the pentastar & the OEM part number (licensed by Stellantis/Mopar) & the McCord part number (licensed by McCord) in the proper font, proportions and location. Dave Wise would probably know best if this is correct! But the logic is there to make this argument.

Why I don't Mark my Parts (Currently)

My main reason for not pursuing licensing was due to the cost it would add to the parts. I restore cars and have done so for 44 years. Parts are already expensive, and I didn't see the value to the majority of customers. This is especially so on these heat shield gaskets where the markings are not readily visible. They are below the manifold hidden from plain sight. (See image below - I used a pencil to try to highlight the markings). I thought the concours restorers would find true NOS parts with the Chrysler & McCord marking and be willing to pay the price to achieve their goals. I wanted to cater to guys like me who want reliable, well-fitting, quality representatives of OEM parts. I might be wrong, and time will tell. I can pivot to get licensing from Stellantis/Mopar and attempt to contact McCord for licensing requirements. This costs money as I would have to pay Stellantis/Mopar & McCord a royalty for using their IP. Maybe a line of those parts at a premium price for restorers? I know the people at Mopar to contact and they explained the process in general but at this time I'm not seeing the value.

Shown above are various heat shields or gaskets - some are for 273, 318 and 340 engines. All were made by McCord. note white part was painted white for 3d scanning - not originally white.