Caster angle is another good place to start looking at. With out enough caster, the steering is extremely light with out any feed back to the wheel. To much caster and the steering wheel pulls out of your hand when returning to zero after a right or left turn in town. Adding or removing caster can change the length of the draglink slightly.
If this was mine, I would start with a shop manual and adjust the steering box. It doesn't matter what you have done to the rest of the steering, if the box is loose or worn, it will never steer right. Pay close attention to the straight ahead adjustment and mark the column and wheel so you know 100% that the gear box is centered. Then, when you attach the pitman arm and need to turn the steering wheel off center to do so, start looking at the linkage and find out why its not staying centered. And never just turn the steering wheel on the shaft to keep it aligned.
Joe
