You need to read the holley book... It DOES matter. If the throttle blades are opened up enough to be into the main or transition circuit, then the idle mixture screws wont do crap. If you can keep the idle speed up with a timing change and lower the idle speed screw so that the blades arent open as far, the idle mixture screws will work better.
Maybe you should take it to someone and have THEM tune it
