FWIW, a well respected indy alignment shop..........been in business for 30 years.........and knows the M/B well..........doesn't use a spreader bar.

Don't know whether he's successful without it, but he did know the caster specs and the fact that the two sides are slightly different on caster...........off the top of his head.

So, I've got to decide whether to trust him with the SD.........or not.