Inner tyre wear is NOT caused by CAMBER.
The R&B shims do NOT adjust the camber.
The problem is the TOE, the cossie uses SEMI trailing arms, so the lower it goes the more toe you get.
The shims from MIKE R adjust the TOE, so it has nowhere near as much, the TOE OUT on the cossie as std is there for stability, and most is taken away with the shims fitted in the UPPER & LOWER hole at the REAR of the hub.
They don't really get twitchy though even with the shims.
I ran 3 1/2 degrees negative on my last sierra, with NO inner tyre wear at all, just normal wear across the tread.
tabetha