What condition do you notice the play under? Off center the steering boxes on the D22 were a pretty loose old thing but most of it should disappear on center.
First up would be to make sure there is not wear in either the suspension or steering linkages that is introducing extra play. Assuming that is all OK and it is wear in the steering box, firstly you need to make sure the steering is on center. Check that when the wheel is centered the steering arm is too, a lot of alignment places used to be in the habit after they did an alignment if the wheel was off center afterwards they would remove it and move it around on the splines to center it up which is a big no-no for me. Steering wheel airbags are something to be thankful for as they largely put a stop to that practice.
The steering box (Or rack) has a high spot on center which is where you are meant to adjust it, if you can't work out where that is you are likely to adjust it too tight. it is easy to re find on most rack and pinion cars as you can just spin the wheel side to side and make sure that it stops and equal but opposite angles lock to lock but with the lock stops on the suspension in the D22 it is more involved to do.
If the wheel and steering box is on center then with the engine not running there is an adjusting bolt with a lock nut on the top of the steering box, you should adjust that to the point that the free play is removed but the steering does not bind at all. if you tweak the wheel a little against the resistance of the tyres it should spring back the other way a fraction. If it does not then it is binding and is too tight.
