72 Duster 340 Pistol Grip Linkage

PcWilliams said

I don't know what it's called but here are a couple of pictures.

View attachment 1715287499 View attachment 1715287500

Click to expand...

The one in your picture is the 71-74 B-body bench handle.
You have got the set up that works best in a A-body, as philcollins noted above.