If it is the steering box, you need to observe the pitman arm along with the steering column and see if they are in sync. This can be a bit difficult to see the pitman arm located at the bottom of the steering box and the column at the rear. You may need a mirror to do this.
Jacking up the vehicle and then moving one wheel while observing the other will tell you if there is play in the linkage. One thing commonly overlooked is the idler arm where it connects to the frame. A loose bushing here will allow vertical movement of the idler arm which changes the toe in between the wheels. This is easier to observe with the method I recommended above with the wheels on the ground.
If you can’t find any loose components, then do this. Get a couple of 2x4s one at least 6’ long and the other at least 30" long. Park the vehicle on level ground, steering wheel centered and tires pointed straight ahead.
Slide the long 2x4 behind the front wheels, on end and up against the backs of the tires with about the same amount sticking out each side. Then place the short 2x4 across the tire, level and sitting on top of the 2x4. Mark the line on the long 2x4 outside of the short one. Then move to the other side and repeat. BTW you can use a 1x2 to 1x4 for the short board if you want or even another straight edge if you have one.
The move the long 2x4 to the front of the tires and a align one mark to the short board. Go to the other side. If you can see the mark on the other side with a gap between the short board and the mark, you are toed in. Make a new mark and then measure the gap. It should not be larger than about 1/8". If it is really large, that could account for the steering delay. But if the gap is bigger that 1/8", you may want to get a good front end alignment. If the toe is off, then other parts of the alignment could be out as well.