Robsinno

Is there a difference in what some called ported vacuum (vacuum gauge line connected to a port on the carb) and manifold vacuum? I recall comparing the vacuum reading on a 4150 carburetor's vacuum port to a vacuum port tapped into a one-inch carb spacer years ago. If I remember correctly, the readings were quite different.

Also, where do most people connect the vacuum gauge line when switching from a 4150 style carb to a 4500 style carb when there is no carb spacer?