Check the caster angle when doing an alignment. The coil sprung (2005+) Superduties are prone to driveability issues when altering suspension.
The draglink should be on the most shallow angle possible. This allows for the greatest lateral power. The tracbar (panhard bar) should follow the angle of the draglink as closely as possible. This is to negate bump steer.
To check for worn tierod ends (tie rod and drag link), have someone turn the steering wheel side to side with the engine OFF. You don't need to make the tires steer, you only want to see it there is movement in the components. Check all tie rod ends, ball joints, pitman arm to sector shaft, track bar bracket, trackbar ends. You can also check the hubs for play this way.