Update - The problem was a previous owner installed one of the megan racing RUCAs with just one spacer. I guess they lost the other and just figured they could just tighten the piss out of the bolt and nut and all would be okay.
Anyway, installing with just one spacer pinched the mount, so I had to bend it back to 90 degree angles. Once I did that, the control arm fit in with both spacers.