Ok, First, the run I posted is with open headers ( no back pressure on the exhaust side). On the carb side, the dump valve ( anti-surge valve ) remains open (Dumps air to atmosphere )until the manifold goes in to pressure - so my lean condition ( about 1200 to 2000 rpm )occurs while the manifold is still under vacuum. Even doing a burnout ( see posted run ) the engine is still under vacuum. The minute I floor it, vacuum drops to 0, dump valve closes, and manifold goes in to pressure - and lean condition goes away. Yes, I am sure about the emulsion sizes I previously posted. So, I went ahead and drilled out the 2nd emulsion hole ( previously plugged ) to .026". Four holes ( top to bottom ) are now .029, .026, .026, and .091. Just ran the car that way. Virtually no change. Lean spot is still there. A/F reading at idle might have gone a little richer ( 12.0:1 to 11.5:1 ). Still open for other suggestions. FYI, shifting at 7K. Will probably go back to how it was and try something else.