According to holley site the 4782/83 call for # 31 squirt and 64 jet center is 355cfm, outer show # 28 squirt & 82 jet 500cfm . I have a set I'm going to try on a sb but last person jetted the outside way down to 72 I think I will go 75 on the outside short and 76 on the long drop side of the manifold.