You may need different shims to get proper valve clearance. Once the new cams are installed, you would use feeler gauges to check valve clearance. The shims are beneath the valve buckets. There are videos on youtube of how to check valve clearance, and swapping valve shims to get proper clearance.Guys just purchaseed some hot cams stg 2, please tell me what I need to install it. What's up with the shimes, do I need it and where do I put them. Help me out please. I want to install them right.