The older Rangers and Bronco II's have a bunch of caster dialed in the front end. Up to 8 degrees is acceptable at lower ride heights. Half tons are less.
Combine that with wide tires and as you turn the wheel the tendency is to stand the tires on their edges.
Steering Angle Inclination (SAI) causes one side of the truck to stand higher than the other side. Think of SAI as the angle of the line drawn through the upper ball joint and the lower ball joint pivot point when viewed from the front. It usually looks like this / \
Caster is the angle when viewed from the side. It's almost always positive (upper ball joint more rearward). I have seen some trucks that run negative caster, but it's very rare.
Think of caster as a dynamic function. It's measured when turning the front wheels, and it's essentially camber change through an arc. When turning the wheel, caster adds to SAI on one side and subtracts from SAI on the other side. That's what causes the lean.
I've found when installing wide tires on TTB vehicles, they will work better with less caster. Camber and toe need to be set very close to zero to avoid the negative camber when backing up scenario.