You can learn a lot about what needs replacing with a really simple check you can mostly do by yourself. Hook up the power steering pump. With the engine running ("off" is fine with manual steering) and in park, get on your hands and knees and look under (not GET under!) the car at the steering linkage while reaching up and slowly, gently rocking the steering wheel back and forth. Look at all the parts that move or deflect before the tires actually move. Next, from above, reach into the engine compartment and grab the steering shaft right before the coupler. Rotate the shaft back and forth like you are turning the steering wheel. You can see if there is extra play in the coupler and the box itself by comparing input motion to when the pitman begins to move.
On my Challenger, I replaced all the tie rods but still was a bit sloppy in the center. By doing the above, i could see that the pitmal was moving side to side nearly 1/8" before the linkage started to move. It felt fine by hand, but under a load from the steering box, it had slop. I also found the coupler had some play in it too.