Rallye dash question

In 71, the Rally dash was standard equipment with a Tach and 150 MPH speedometer in the 340 Duster. It ended completely in 72, no option at all, and that was 1 of the reasons I bought a 71 340 Duster. Also the 10 to 1 compression was a thing of the past. Chrysler could have offered the rally dash as an option from 72 on, but didn't. There would probably be a lot more of them around for us now if they did.