Identify this tranny?

I recently met a distant neighbor who bought a new '71 340 Duster "grandma appearing car" with a hurst shifted A230 close ratio and optioned with 3.91 sure grip. Medium brown car with cream beige 340 callout stickers and stripe package, brown bench seat interior, rubber floormat, radio delete, all manual car and then day two'd it with headers, intake, cam. etc. He stated that it surprised a lot of people who claimed to have "fast" cars, lol!