I think there are 2 flavours that fit all SC430 models. Lexus upgraded the shocks but they are all similar to fit the same chassis whether an early or later model. Yes damping can be set to maximise comfort. On standard wheels and tyres, I found the front can be set firm and still be comfortable, less firm made little difference whereas the rear was best set around the mid-point for the ride to be acceptable.
Well worth upgrading the rear anti-roll bar to limit the sway too, yes it improves the handling but I think it improves the behaviour for comfort too.
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