What PARTS did Hurst and Chrysler put in the Super Stock Barracuda & Dart not in other factory cars

So here’s a question… did these cars come with an aftermarket Tach or did the drivers add those themselves?

I’ve seen some original cars with Stewart Warner Tach’s and Synchro-Start units. I also heard somewhere else that they had Jones Motorola Tachs.

Can anyone shed some light on this for me?