Have you disassembled and inspected the tie rod ends and the drag link ends and then reassemble and adjust them to specs?
Have you disassembled and inspected the front leaf spring pins and bushings?
Are your kingpins in new condition?
Are your wheel bearing adjusted to specs?
I would check all of those items first.
If the wobble doesn't go away, then I would inspect the steering box to see if it is set to specs. I'd save that for last since it is more complicated to work on and labor intensive than the other items.
I work on trucks just like how I shoot pool. "Shoot the easy ones first."
