Originally Posted by Harvard
Is this a Ford or Chevy chassis?.
I'll refer to the title: " E350 ford chassis"
First thing I would do is check the front end components for age/wobble. 45k doesn't mean much... Tie rod ends, steering joints, etc - make sure everything is tight.
Next step - order caster bushings.
Next step - have it aligned, preferably while loaded. As the shop to use the caster bushings to push toward the positive range in the Ford spec.