Edelbrock 600 carb issue?

May need a different step up spring on the rods? Open this link and go to page 8.......
http://www.google.com/url?sa=t&rct=j&q=&esrc=s&frm=1&source=web&cd=1&cad=rja&ved=0CCAQFjAA&url=http%3A%2F%2Fwww.edelbrock.com%2Fautomotive_new%2Fmc%2Fcarbs_acc%2Fpdf%2Fcarb_owners_manual.pdf&ei=VW1SUJrTBYTk8gTR-YGABQ&usg=AFQjCNHL_Z4CI2CICFonVf1CVlgfuSnMeQ

Although i can't explain why it's a recent issue.