Vague Steering, How to improve?
The 0 toe is a problem. Not saying it's the only problem, but it is a problem.
When your wheels are rolling down the road they tend to pull all the slack out of the rest of your steering system, tie rods, etc. The tie rods do have some play, and even a small amount x 4 different tie rods ends can be significant. That's why toe-in is specified in the alignment. The wheels start with a little toe-in, so when you're rolling down the road and the tires pull the slack out of the system your tires are actually straight ahead or close to it.
With zero toe-in, when you're rolling down the road you probably have a little bit of toe-out, which will make the car feel flighty and loose.
With all the other new components, I would be looking at the steering box moving on the K frame or the steering coupler as Del suggested. Another possibility is that the steering box mount on the K frame is cracked, I had that issue on my '74. Steering was vague, seemed like a lot of input was necessary before the wheels moved. Had a helper turn the wheel while I looked at the steering box, the entire steering box and mount was moving and opening up a crack in the weld where the steering box mount was welded to the K frame. Factory weld had failed.
For what ever it is worth i just tested and I'm getting 5.75 turns lock to lock., 24:1
He's measuring from center to lock in each direction, and probably not counting part of the on-center dead spot.
Stock 24:1 is about 5 1/2 turns, 16:1 is close to 3 1/2, and the aftermarket 20:1 is about 4 1/2.