You will probably need the entire quantity of Sodium Sulfite indicated in the formula. I don't have it in front of me right now.
But, pH is critical. CD4 is an acid salt of an organic base, but the part C is the free base of CD4 with Bisulfite. So..... I cannot give you exact figures. Kodak Powders and Solution division had it figured out based on their formulas, but I, alas, do not.