Need help with Ridetech upper control arms.

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I am working on a 68 camaro. I have the full front suspension from ridetech...even the true turn. I have noticed my controls don't set even. After investigating it's the frame holes thats off from the factory. My question is i read in the instructions ridetech makes different caster slugs for the upper control arms. Could I use those to even out the upper control arms? I added a picture also.
Thanks, Josh T.