I give up

[Woodie1]

Our 1930 A will not idle down without quitting. I have plugged the vacuum wiper connection at the manifold & it made no difference. I removed the intake manifold & filed the connection for the carb flatter & installed new carb gaskets at the bowl & mounting flange. I have removed all jets & made sure they were clear. The float level looks correct. With the upper half upside down I measure 1 1/4" to the gasket surface from the solder line & it measures even on sides & front of float. The timing is good. The engine is a touring engine with high compression head & has about 5ooo miles on it. The throttle shaft is free in the housing with no slop. It's been dying at stops lately. It wasn't doing this before. I have always had it idling a bit fast but now it's worse. I just don't know what else to try. The carb was rebuilt by a reputable Model A parts supplier about 4 years ago. It doesn't drip gas when sitting. I do shut the gas off. when done driving it.