Simple coilover adjument question

[Onefast99gsx]

Went to lower the rear supspension last night and i noticed the coilover adjuster was down as far as it would go. That sucks! I probably have 1.5" or so between tire and fender lip. I really wanted about .75".

I have Tokico Illumina 5-way gas shocks and Eibach springs. I "THINK" they are the pro-kits. They say 22/99 on them. I don't know what that means. I measured the free uncompressed length of the spring and it was exactly 7"

So if i want to lower it more do i just need to change the spring to a shorter one? I have all kinds of adjustmen room in the front. It's just the back which is odd.

Thanks.