[sick472]

My single snorkel will not fit on my Edelbrock without the spacer (on my 72), nor will the stock breather fit on my Holley on my 85. The bottom of the breather hits carb mechanisms and needs some amount of upward spacing. This may not be the case with Quadra-Jets, but I'm not blessed with those.

One might argue some advantage due to more laminar or less turbulent air flow from a spacer, but those benefits will be very minimal and only really count when squeezing every bit of HP out of a race engine.