You're 100% right about the PO. On my rig, I needed the C&T to help fix the caster. I'd bet I'm not the only one.
Why are you planning on doing a C&T if your caster and your angle are fine?
jsut because the caster and pinion angle are factory, doesn't mean they're fine.
here's factory pinion angle and factory caster. the driveshaft would actually have a bit more angle to it but, it's not actually bolted to the t case...it's down a little from where it needs to be. it won't bolt up. there's not enough angle allowed in the yokes. even if there was enough to allow it to bolt up, this is sitting in the driveway. as soon as the front end drooped a bit, the d/s would bind.