There is a Low Top and a High Top BBD 2 bbl.
The actual carbs look the same to me, same overall height.
The difference is High Top has the Higher Fuel Bowl extension on top.
Low top is level with the top of the fuel bowl and vents out the top of it.
As pictured here:
View attachment 1716033148
The 2 carbs on the right are the Low Top BBDs.
You learn something new everyday.
