I have a '97 1200 with a Dale Walker Stage II, 5 degree advancer and D&D bolt on can that is finally spot-on. I messed with the set up over the past 4 years and could never get it right. I had a bad stumble at 3,000 - 3,500 rpm. So when a friend dropped by this week we decided to pull the carbs and start with the initial set up. Dale Walker recommended 150 mains, 35 pilots, needle in the center slot with no shim, and 3 1/2 turns out. (That was my original set up when the bike had other stumble and over-rich issues.) Guess what? No stumble, pulls much harder, and my milage which was NEVER better than 33 jumped up to 44! Go figure? It may have been that the engine had so few miles on it when I first put the kit in, but other than that I can't determine why it is running so good now when it didn't to begin with.
As far as 4 shims? I think one per needle - 020 generally, but I remember with stock exhaust, stock needles, and an airbox mod you can go to an 060 shim if needed. (in place of a needle with multiple slots)