I'm chiming in late here; hopefully you've already got it figured out.

This is a real long shot (save it for last), but my bird sat just a bit lopsided when I got it, about a 1" difference from one side to the other, and only in the rear. So one side looked fine from the side, but the other had too much clearance above the rear tire.

It took me forever to figure out that the leaf spring bracket on the driver side was the wrong part. Had almost the exact same shape, but the bolt for the spring was an inch higher/lower (forget which) than what it should have been. Not sure, but I think it came off of a Nova (?). Once the correct part was installed, all was well.