how do i know what spacers to use on my mm caster camber plates

There has to be at least 1 thin spacer under the bearing.

Call the MM tech support line, they will help you and they are great people to deal with. Only costs you a few pennys for long distance.

You start with a small spacer at the bottom, with the other three above the plates, then slowly close your hood to see if you have the required 1/8" clearance, (use something like play-doh or putty) if you don't have enough clearance, take the next size and place it below the plates on the strut shaft. Thats all.

The directions are on the website and are very detailed.

Here's a link to yours (I hope since your sig states a 1990, and i'm assuming you got the right kit)

http://www.maximummotorsports.com/content/install/pdf/front_susp/MMCC9093r6.pdf