Top suspension arm - identify left & right

[David Robertson NZ]

Hi,
I think I messed up putting my front suspension together. I've just had wheel alignment done and they had to pull the lower arm as far forward as adjustment would allow to get castor into spec. That means the sway bar links aren't vertical - they lean back a lot from the arm to the end of the swaybar.

I'm thinking I've got the left & right upper arms mixed up. Just going by eye, it looks like the balljoint is further forward than the center point of the upper shaft. If it was back rather than forward, lower arm could go back as well and everything would line up.
Does anyone know how I can identify left and right arms while they are on the car? Am I correct in thinking the balljoint in the upper arms are off-center, so getting left & right wrong would put the balljoint forward?

Also the spring saddle has one bushing lower (further from the spring) than the other. Should this be towards front or back of car? I know one of mine is wrong because I've got it towards front on one side and towards the back on the other.

[Aaron65]

I had wonky caster settings from side to side on my car when I bought it as well, so I did a lot of research about the upper arms as I scratched my head over that one. From what I could find, and from my staring at them side by side on the garage floor, they are identical and interchangeable. It's been a few years, but I believe I even talked to a few salvage yards with Hollander manuals.

[Karl]

G'day.
According to the master parts catalogue they have different part numbers.
I was under the impression that they are not interchangeable.
Karl.

[Aaron65]

I went back to my forum comments (on various forums) from 2019 when I was dealing with my cross-caster problem, and you're right, Karl. The Hollander manual does label a different part number for each side, but I'm still not sure why. They looked exactly the same when I lined them up.

For the OP, I found that someone had replaced my car's upper control arm shafts at some point and they weren't centered as they should have been, so that's something you may want to check.