65 Steering Box

[mygt350]

Ford produced three different steering boxes for the 65 model year.
1. HCC AW, Power steering, 16:1, 3 3/4 turn lock to lock.
2. HCC AX, Manual steering, 16:1, 3 3/4 turn lock to lock.
3. HCC AT, Manual Steering, 19:1, 4 5/8 turn lock to lock.

The 65 GT350 was shipped with the HCC AX box with the unique pitman and idler arm to quicken the steering even more.
Is there a difference in the HCC AW and the HCC AX 16:1 boxes? If so, what is it?

Second question. What determines the ratio? Is it the worm gear at end of main shaft or the block gear with the ball bearings or the gear at the top of the pitman? Or all three. Is there a difference in the cases for manual versus power?

Thanks