Just going 'large' on the ARB (front and/or rear) without doing similar on the springs and shocks will most possibly upset the whole caboodle.
The ARB is basically a spring straightened out . As an example , on my 2006 S203 C55 AMG the bars are much thicker and solid metal compared to the skinny hollow ones on most of the other S203 C class cars of the same era .....that do not have a 5.4 V8 engine (all of them) . Same goes for the springs on the AMG , very different.
Whether spending big money on 'upgrading' the suspension on a 2001 CLK is worth the money is , of course , your decision. Probably plenty stuff out there.
As an aside when I wanted to renew the front ARB bushings on my C55 they were no longer available , only bonded to a new ARB . Instead I went for the 'softest' Bushes that PowerFlex make for my car. Shown here , I can't feel any difference . Genuine MB AMG springs and Koni gas struts were also installed , along with Lemforder top bearings and new bmp dampers.
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