setting the lash in 8 3/4

I think I can get my hands on a magnetic dial indicator. So you're saying tighten one adjuster to push the ring gear to zero lash on the pinion. Then tighten the other to push ring gear away .006-.010 from the pinion, while not moving the the first adjuster at all. correct?

You need to indicate on the ring gear. The .006-.010 will be the distance the ring gear rocks back and forth rotationally against the pinion.