I never seen yet, a quadrajet that the secondary shaft and butterfly’s did not work because you have a actuating lingage arm that goes from front shaft to the secondarys. It’s almost impossible for me to understand this statemant when guys tell me this. It’s almost like progressive lingage, once front opens up to a certain degre, from that point the secondays always open.Now opening up to a full 90 degrees is another issue.I guess you could remove the arm making the carb. Act like a 2 bl. But why would anybody do this, is beyound me.