I have tried that to. I heard the pros shave some off, but they do keep there shocks fresh. I think I was around 3.2mm. I cant remember. I am wanting to find something more consistent and accurate 1000th's are tough for me to measure, I had trouble getting them mic'd the same. What grit do you use. I was using 800 grit. So far the best over all performance and consistency has been the stock building set up for me.

Edit I found my shims (Middle) 3.2 mm. Sound like to much?