"Detent" usually means the shift positions that fall into place on spring-loaded detents on both the shifter side (user) and the valve body side (tranny). You adjust the linkage so they line up. My 3 classic Mopars use a cable-shift that is easy to adjust. I have never adjusted a lever shift like in your 1973 (assuming). If you don't take the time to ask clearly and grammatically, don't expect answers.