From what I understand..
The larger brakes of the 400/500E's will not clear the older replaceable ball joints. But you can make it work with the older style by grinding some tab down. Or just get the welded ball joint control arm. Is there a price difference?

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08 R320 CDI current

Past
95 E420
87 300D Turbo 5spd
90 300TE
83 300SD
85 300TD
92 400E
85 190D