Convert 5" Z1 to 4"...

[HardcoreCrash]

I've got a '99 Z1 QR20 5" that I want to take down to 4". what parts do I need in order to do this? is there a kit? and what exactly is the procedure? just a simple spring change or what?
Thanks
Crash

[gravity]

you can buy different length positive and negative springs to shorten the travel, the negative spring will be longer than your current one and the positive spring will be shorter.

coulda sworn i answered this already....