Turn the wheel a 1/4 turn either way then tighten the set screw, It will have a "feel" when it seems binding. The reason for the 1/4 turn is that it makes play when the box is turned. It's tighter between the teeth, when pointed straight ahead.
1968 cuda has junk yard 16:1 old aluminum box, it is maxed out down to where the screw head slot is even with the set nut. It needs to be rebuilt the next time it gets loose. I have the Flaming R. u- joint conversion. Now, on an Abody that thing takes OUT all the fore and aft movement, that will be needed for a wreck to bring it to the side safely. I would not recommend it.
In the case of the collapsible spring loaded steering shaft on the 1974, the u- joint conversion is perfect. This heavy 440 car uses the Flaming R. iron 16:1 manual box. Man, those FlamingR's have gone up +30% since I bought. Even the new box needed a half turn to take out the play after a year. The best box is that original power steering 16:1. I have the Mopar factory rebuilt one I had to exchange after driving down Jack London's Glen Ellen, Ca. hill in 1974, with out the motor on, that damaged it, and gained much too play. Power box is eventually going back in; and I will get my money for the Fl,River box on Ebay. It's insane, the amount of strength to park that car now. Wife can't do it. Good for going straight at the track without an extra belt to suck power.