Is your truck still sitting fairly level? If so, you haven't changed the caster angle, and I would think the shims you have in there now are correct. But, if you need more shims, any spring shop should have them. You can cut down a wider shim with a cutoff wheel, just cut a little off both sides so the alignment hole stays in the middle.
The only reason I can see for needing more caster is if the truck has a rake, or a nose-down stance.
Last edited by waldo53; 01/10/2008 5:36 AM.