Cannot get right rear alignment in spec
 

I have a 1990 Miata B-Package with 111K miles that I just bought. Trying to get this car all sorted out before regularly driving. Suspension is all stock (and appears mostly original) aside from Tokico blue shocks (I know, they are junk, will be replaced as soon as I have the cash)

Anyway, I went to perform an alignment today (just setting it to stock at this time). The left rear caster and camber was in spec but the right rear was out by a mile. About -1.2 degrees of camber and 1.75 degrees of toe-in. No amount of fiddling with the cams could get it anywhere near spec. I could get the toe down to 1.00 degree, but then the camber would go to -2.25.

Question is, what could be causing this and how can I correct it? Or rather, what should I be looking at/for? I'm thinking that I have something bent most likely. And that I should probably upgrade the eccentric cam/bolts while I'm at it. (One rotates the bolt head when I turn the jam nut but the cam doesn't always turn.)

You should rotate the cam bolts from the head of the bolt side, not the nut. But it sounds like something is bent.

Control arms are designed to bend before the subframe, so if something is bent it's not a huge deal to fix.

I guess, but so does the long bolt and the upright. I have a rear ABS upright that does not get less than 1/4" of toe out no matter what you do.

That's what I was doing, or rather attempting to. When I would go to turn the jam nut, the bolt would also rotate. I tried holding the bolt with a breaker bar while backing off the jam nut but they appear to be rusted up pretty bad or otherwise messed up

Partsgroup has used (but decent) alignment bolts for something like @2.50 each. Do yourself a favor and replace them. Also, I'm sure they have control arms for a decent price. If you even suspect it's bad, replace it.

Yeah, I figured on getting the bolts. Another tech at work (with much more experience than I) wants to take a look at it today and see what he can do. I hate to just throw a dart and order a control arm without knowing if that's the problem first.

Had the car back on the alignment rack today. Took a bunch of measurements and concluded that the rear subframe, lower control arms and upper control arms are not bent. Only thing we could not measure is the rear spindle (due to it's design/nature). He came to the conclusion that the only thing that makes sense is that the spindle is bent on that side. Anyone had this happen? Are these still available new? Are they specific to the '90-'93s, or are they the same on all NA chassis?

All NA are the same. Call your favorite miata salvage place and get a new (used) one. Make sure to get a new long bolt with it, in rust states the rear long bolt and upright like to become one piece. And the bolt also likes to bend as well. My upright was visibly bent in the bottom two tabs and the assembly didnt go together easily with the bent one.

I just recalled that the wheel that was on the RR when I got the car was visibly bent. I bet that whatever happened to bend that wheel was what bent the spindle.

Tore down the rear suspension last night. Discovered that the bolt holding the spindle to the lower control arm was all bent to crap. So, going to try replacing that and the eccentric cams and see where that gets me