Ford Holley Carb on V8 - pipe over choke?

[Lauren Child]

I'm taking a look at my carb (Ford 94 21-29) on the CMP. The one I've got has a pipe at the very top poking into the airway above the choke plate.

The spare 21-29 carbs that I can find on the net don't have this, and it's not shown in the illustrated parts list that I have to hand.

Does anyone else have this or is it just me? What is it for?

[Lauren Child]

Ah - I just found one with it so I'm guessing it must be a production change. What is the pipe for?

[John Mackie]

Hi Lauren The carby top that you have is INTERNALY VENTED to the float bowl. the other type is EXTERNAL VENTED. the vent is located in behind the choke lever. the internaly vented type is less suseptable to air-cleaner restrictions.

[Lauren Child]

Thanks John!