Adjustable trailing arms

[infinity]

Hi, im looking at making some adjustable trailing arms but underneath it looks like there are four? could have sworn the whiteline kit only had two. So what im asking is is it necesarry to adjust all four

 

[pollyp]

just need to adjust the lower 2 arms
https://www.micra.org.uk/threads/pollymobiles-rebuild.35251/#post-381117