How do they all differ from 1949-56? You often read that a car has a '56 steering box, are they different?
F-1 used a tapered spline shaft with nut on the end. F-100 straight shaft with a pinch bolt on the pitman arm,also mounting flange was larger.
From what I know 49-52 are diff, then when they went to the F100 in '53 from the references that I found they are different.
Another big difference is that the later F100 boxes have the input shaft above the sector whereas on the F1's the input shaft is below the sector like pictured above. It can make a difference in pedal arrangement and head/header fitment.
The F-1 is actually 1948 - 1952. Like Thunderbird said, the worm/shaft is below the sector on the F-1 box. Depending on the installation, this can make for a steeper column angle. One neat thing about them is that the worm & sector gears from 1937-1948 p***enger car (cross steering box) will install and steer correctly in the F-1 box because the worm is below the sector. The F-1 box I acquired for my roadster had junk gears in it and I was able to harvest all the internals from a pristine '39 cross-steer box.
Yep, and you can usually get the 37-48 boxes pretty durn cheap too! You can also use the pitman arms from them on F1 boxes if you're using regular style tie rod ends on your draglink.