shorten turning radius 1950 F1 all original truck
 

How much can I trim off the steering stops [the long nuts on the king pin bolts]?

Re: shorten turning radius 1950 F1 all original truck
 

trim off to much and tire will probably rub the frame behind the wheel.

Re: shorten turning radius 1950 F1 all original truck
 

Replace the long nuts with coupler nuts from the hardware store. Grind away on them until something rubs. You might be able to make an adjustable stop using jamb nuts and dial it in. I don't recall if the lock bolt is fine or coarse though.

Re: shorten turning radius 1950 F1 all original truck
 

The steering gear is approximately 4 1/2 turns lock to lock internally, you might check this before you mess with the spindle stops. You don’t want the steering locking up internally because the spindles are turning too far.