What's up with THIS?????????

[1975stepside]

OK, my old automatic transmission shift-indicator never did work right since I got my truck so I bought another one. But the cable seems to be too long, just like the old one! My 75 Stepside has the usual place to connect the end of the cable to the steering column, a slot about 1 1/2 inches long positioned at about 3 o'clock on the right side of the back edge of the steering column.

I made sure I got the shift indicator mechanism for the 3 speed automatic (with NO overdrive), and it looks just like the old one, only the indicator needle slides properly whereas the old one didn't.

Am I doing something wrong? Does the cable go somewhere else first and THEN connect to the column? I really want to have a working shift indicator, I know enough to just count up from "park" the right number of gears, but when my daughters borrow the truck, they end up driving around in second gear a lot. Can anyone help? Thanks!