Big Block Rocker Shaft Shims

I have used the shims to get the valve train geometry exactly were it needs to be. You need to move the rocker shafts up off the rocker stands to move tip of the rocker arm so that it meets the tip of the valve a little off center to the outside. As the rocker arms pushes down on the valve the tip of the rocker arm moves back toward center of the valve tip This lets the valve move straighter in the guide with less friction and less wear and tear on the guide, and that means more HP and a longer life for the valve train components. Maybe this will help answer your question. You can get a shim pack from 440 Source