[drolston]

I have the same setup except for a Schneider 248F cam, which is slightly milder than the Max 1. Both good street cams. In perfect tune and no sticking valves, I still get flutter on the vacuum gauge at 650 rpm idle between 14 to 16 inches. With these cams it is never going to be rock steady at idle.

Is it correct to assume that your end carbs do not have idle circuits, or if they have them, they are closed? All idle adjustments must be done on the center carb with the throttle plates on the end carbs adjusted so that they are both absolutely and precisely fully closed. Absent that precision, there is a vacuum leak that makes idle adjustment futile. If you have the cheap progressive linkage, get the expensive one. Take the tops of all carbs off leaving only the cast iron base and linkage. That way you can see the throttle plates and make the linkage adjustments to get precise closure of the end carbs. Be sure to use throttle return springs on the driver side of the throttle shafts of all three carbs. The linkage must operate very freely. Any misalignment may cause binding that could prevent reliable closure.

Another warning on those 9Super7 carbs: double check the float level. I have those carbs and the float was way off on all of them. Carefully heed the warning on how to make adjustments. If you bend the tab without protecting where it joins the float from stress, the float seal will fail and sink the float, flooding the engine. I also replaced the needle type float valves with the Grosse ball type float valves. Less prone to stick closed and less susceptible to debris. I learned all of these lessons the hard way, but now the performance is great and reliable.