Vague Steering, How to improve?

First thing I would suspect with all those new parts is a steering box LOOSE ON THE MOUNTINGS. This does happen

You need a helper, wife, etc, or if you get ahold of me I might. (Broken ribs LOL) Anyhow, with someone working wheel side to side, get a light and get dirty. Start at coupler, look carefully at upper shaft and coupler for play between the two, then play between coupler body and box shaft.

Then look at pitman and steering shaft. Almost exactly as steering shaft moves, pitman should follow with very little delay Look for play in the lower bearing where the pitman shaft exits the box. Side to side or up/ down.

Now get underneath, look at pitman shaft and pitman, then center link of pitman and end joint. In other words, one step at a time look at every single joined piece that moves in relation with other. Look for play and especially up/ down movement of idler arm.

Tires can have a tremendous effect. Cheap bias tires can "feel" as if they are adding play as can "drag race skinnies"

Look in the shop manual for the procedure on box adjustment.

I did basic simple stuff to mine before I tore it apart, and it turned the thing into a different car. Rebuilt front end, stiffer T bars and front anti sway bar made tremendous handling difference

If you are running an odd combo of mismatched front/ rear tires, and or problems such as rear shackles can, believe it or not, "transfer" the problem to seemingly a front problem.