Wanted: Cab 13 steering gear

[BCA]

Sounds like an easy question about steering gear but a review of the (rare) Ford Master Assembly parts book shows a wide range of steering gears used on Ford CMP's. I don't have hand-on experience with these steering gears but do have a spare NOS C111QF 3503 steering gear, apparently for Gun Tractor model. F60L trucks use 11QF-3503A, C29QF-3503 and C01QF-3503 depending on motor serial numbers etc.
Perhaps someone can explain just how interchangeable steering gears in actual practice.
...... Brian