I have a very early all original 12 bolt posi rear with 3.31 gears. The housing matches the internals. It has a PF 09 20 stamp. The ring gear is dated 6 66. It has no traction bar provision and has correct monoleaf mounts. Can you guys give me an idea of value? Or maybe give me an idea what engine combo it came from? I was thinking about $1200 to $1500 maybe.