Cuda Quarter Window Regulator Spring

[Scott G]

I am looking for a spring for a quarter window regulator on a Cuda.  The one for my driver side regulator is missing for some reason.  It is specifically part 25 on the diagram.  Parts book shows cuda and challenger used the same spring part number.

Alternately, it looks like the later year regulators don't have the springs on them at all.  Are they really needed?

[Cuda Cody]

Can you post a photo of your regulators side by side?

[Scott G]

@Cuda Cody
The first picture is my regulator that is missing the spring.  You can see the longer pin on the pivot point that the slot for the spring and the longer pin at the end of the arm for it to hook to.  The second picture is borrowed from eBay of one like what I pulled out of my friend's 74 challenger yesterday that doesn't appear to have ever had a spring on it.