Stiffer suspension would usually almost always result in more rattle and NVH, whether it is lowered or not.
Additionally, I'm not too sure about the use of King ultra low springs, they tend to be so low that you aren't going to get much suspension travel, which would aggravate the any NVH issues, not to mention adverse handling.
Whether or not I have answered your question, I dunno
But that is my take.