Geometry is a part of wheel alignments and since I am an Alignment Technician at my day job, I felt this adjustment should be as accurate as possible.
I found in an installation pdf that mentions the adjustment for our Mustangs would be 4-7/8 inches from the center grease plug to the center line of the left inner tie rod ball socket (see first image attached).
I noted when I disassembled the valve from the center link (prior to restoring the parts) that it was 28 turns in before. That seemed good enough too but I thought this too should be checked with geometry.
I begin with a centered steering wheel, centered with the properly adjusted steering gear box also centered. I also installed and torqued the center bolt-in crossmember in case the frame is bowed. Using the lower control arm cam bolt slots as a fixed point to measure from (each side), I took cross measurements to the opposite side inner tie rod holes (I fit a small socket inside the hole to aide in taking the measurements). I also used a deep 3/4" socket pressed tightly against the frame (as seen in my pictures).
Seeing my measurements were off about 3/16" side to side, I needed to back out the control valve two turns from the previous assembly settings to get the measurements evenened out. This process gets the setting confirmed to the center of the frame, not just a random number. I like that better.
