Step up spring clarification? AVS2

It should tell in the instructions or may be download from Edelbrock's website. I just printed off the tune directions for my 1406's. I have glanced through the instructions but haven't studied. I did see a chart where it carb adjustments are in the center and it tells you what direction to go if you need rich or lean. It seems to be a bit confusing if you are just adjusting by the seat of the pants.