The Ingalls kit #35700 allows for independent camber adjustment on both front and rear bushings. Obviously you can set both equal inwards or outwards.

What is the net affect on alignment if they're not set equal - one pushed inwards, and the other opposite? (on a single arm). Caster perhaps?

 

Yes caster. Also, increased bushing wear since the bolt will be placing continual pressure on the bushing by being off axis.

Those make it very difficult to keep the correct caster setting. You'll want a patient alignment tech who is willing to spend the time doing it correctly. It's that inconvenient.

I drove for a few weeks with those. Never again. 0* caster on one side and +1* on the other makes a rather difficult to drive car. And the tech spent over an hour trying to get them even (not saying he was particularly good or anything, but most aren't that concerned)...