Have a set of s/s springs on a Dart GTS I purchase. They are 6 leafs. There are thin shims on the driver's side. Is this factory? Car was a drag car most of it's life. Didn't know if a racer installed them.

After cleaning I see where the thin shims look like there galvanized and are on both springs. Numbers are 3722293. 36369. 020 4 Both sides are the same

There's an active thread in moparts Q & A about factory leaf springs and part numbers. Could ask there. I'm not sure if the spring part numbers in the books are the same as the stamped numbers. Could be a digit off or something like that. This happens with alternators as well. But for those there's bulletin explaining that. *If you're not on moparts and/or don't want to join. Post the picture of the stamping, and the car info (year) and I can ask.

OK. Best I can tell, the last 3 digits of the stamped number matches the sales order/ build order code. In other words, if we looked at a broadcast sheet the three numbers under spring will match the last three digits of one of those stamped numbers. According to this post, one of the stamped numbers is probably a date code, and the five digit is vender code. https://board.moparts.org/ubbthread...ication-for-what-application.html#Post2582916 So you're looking for info on a 293 or 293/293 More on the codes and stamps in this one https://board.moparts.org/ubbthread...3/re-leaf-spring-part-numbers.html#Post159513 The part numbers in the parts book are not the same, and so far I don't see a published cross reference. Best will be to find a broadcast sheet or a photo of one. Here's the discussion. https://board.moparts.org/ubbthread...-part-number-chart-available.html#Post2719112

I posted your spring's numbers over there. We'll see if anyone recognizes them. According to the parts books, a 383 would get spring pack p/n 2808 677 which used main leaf 2808 678. Only 383 springs use that main leaf. (maybe in '69 440s did too) According to examples posted, those springs were stamped xxxx 056 Interesting that Stengle Bros replacement shows both the part number and the stamp number. 78-581 Leaf Spring Assembly Some comparisons can be made with this chart Dodge Lancer Dart and Swinger Leaf Springs - Stengel Bros Inc.