Nope it's perfect at cruise and wide open throttle. Basically got all figured out except the extremely light throttle froma stop. Going lean then but all other areas are great.
At that condition the pump discharge may be nil to dribbling down the venturi, that transition is supposed to be covered by the transfer slots or "T-Ports". If the throttles
are opened too far to maintain an acceptable idle speed, You will be setting the idle mix with the slots partially exposed already, so they can add very little at "tip-in".
If they are, You may need to add or enlarge holes drilled in the throttle plates, even a 1bbl slanty has one drilled in it. Even though I'm certain You've checked, a slightly
low fuel level will cause a sag, because it delays the start-up of the main circuit discharging. Just some things to look at...................