Sorry, but I have a dumb question.
I bought ground control camber caster plates for my fc. They did not specify a direction on the mounting, but my guess is that the factory mounting holes are for the castor and the middle slotting is for the camber??

Only reason I am thinking the middle sliding is for the camber because there is more adjustment on that vs the slots on the factory mounting holes.

 

That is correct

 

Theoretically you could do it either way, but yes, that's how they're supposed to be.