How much RPM drop from park to drive with stock type 340 convertor

Bear in mind that some old carbs actually adjusted idle speed with an air leak. The old AFBs some models (I don't think Mopar?) had a great big screw in the middle between the two idle mixture screws. This set idle speed. EFI works the same way. The IAC (Idle Air Control) sets idle by leaking more or less air into the intake. The EFI corrects the mixture and ...........it........idles

Here's one now.........GM application Notice there IS NO mechanical idle speed screw on the throttle lever

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