Thanks for the comments, Jon! My main concern about low speed and midrange is more about the nut behind the wheel than the actual physical setup. When the thing doesn't pull as expected, the natural tendency is to pedal it a little harder, which kills the manifold vacuum and the venturi velocity. Very few drivers ever learn that there are throttle positions other than wide open and idle. Even if that perfect balance between right foot and vacuum gauge can be achieved, few if any drivers ever find it. The resulting flat spot and lean backfire is what puts those scorch marks in the paint on the hood!
Jerry