I’ve pressed out many a pair of LCA rear bushings and they all have slide grooves possibly from dirt and stuff while pushing it out!

 

Here are empty bores on my LCAs. Note the uniform spacing of the scrapes. Can't be random. I am pretty sure the factory makes the bushing faceted to allow more tolerance in the bore. (cheaper) LIke bearing tolerance rings.

https://www.bearings.saint-gobain.co...ce-ring-styles

 

I put the new "Problem solver" rear bushings in my old arms and the suspension geometry is back where it was. During the swap I compared the import arms with the originals. I was wrong about the die casting. The casting looks identical to the original and makes me wonder if it came from the same tool. How ever the ball joint was not the same. The import ball joint is .130" longer, as measured from ball canter to middle rivet. That is what caused the -3 degree camber. Another issue, which made installation tough, is the sleeve in the rear bushings. .200" longer than the new ones.
The caliper is set at the dimension from the original arm. I slipped a little off center when I took the picture.. But .130" is hard to miss.

 

So the ball joints are close but not exactly the same.