I hav an old defender 90, and i noticed that the casing to the shocks has startd to rust through, which started me thinking about replacing them. I was intending on replacing them with de Carbon shock and i was wondering if any one had an opinions regarding whether its worth it, or if ill have to replace the springs as well 2 benifit?? and also are de Carbon gd value or our there other better shocks out their that you would recomend?? Thanks for your time.