Stock type suspension spring with 4 kg/mm or more rate?

[jafero]

I have two rear KYB AGX struts.
I am looking for springs. Because I have two megan front struts with 6kg/mm spring I would like to put 4 kg/mm or more rated spring on the SGX struts.

Do you know any springs with 4 kg/mm or more for stock type suspension struts? Where can I get them?

[aznpoopy]

i believe eibach sells custom rate springs.

[punxva]

hey, since its early ill be nice and not flame you for not searching, but heres a link to my suspension faq where ive listed most of the major spring manufactures, and spring rates...

http://www.zilvia.net/f/showthread.php?t=115916