Sorry to resurrect this one but I'm at the same point where I'm looking for the speedometer cable clip as shown in the attached picture.
In the picture at the bottom is the rag joint. Lower left bolt is for the parking brake. Brake lines go from left to right. Speedometer cable running mostly vertical.
The clip is about dead center. This area is below the power brake booster.
This was a rather long post, and would summarize it this way:
1. The clip nor the butterflypush pin is not limited to 65-66 nor the NJ assembly plant. I'm sure that this is how my Dec 66 SJ 289 car left the factory.
2. It is not limited to C6 transmission speedometer cables
3. If still does not appear to be available. I can see why Tim Lea would make it, it not too complex of a shape. The butterfly push pin is available separately from NPD if I recall.
Since it has been a few years, does someone have a source, or have a used one available to purchase? Otherwise I'll make a few to share with others.
Naturally the one in the picture is MIA, I guess I need to head back to the shop and look much more closely. Time for spring cleaning.