What's this port for?

[JackFish]

How does this get hooked up? What does it go to?

 

[LameHoof65]

Looks like where your choke shaft and spring go? it doesn't appear in the picture to line up quite as I would expect....but then I am a novice at carb stuff for sure... It's probably called something else altogether. And you have an elec. choke...beats me, jackfish---unless it had an old water choke and you did away with it---maybe then you just neet to put a plate over it.

 

[lightnin-boy]

I've seen these cast bosses in later holley/weber 5200 carb bodies. As far as I could ever tell it does nothing and covering it up is probably a waste of time.

Kirk

 

[addo]

I reckon MarkP would know.

 

[JackFish]

It's off a 78 pinto, if that's any help.
Here's a different angle:

 

[simon]

smog voodoo.

the holley 5200-series carb was the basis for the holley 6500 feedback series, i.e. 6500 and 6510-C.
During production, air horns were used for both applications. While this cast boss remained unused on regular 5200 applications, it carried a feedback diaphragm and needle on the feedback versions.

 

[JackFish]

So it is a useless non-functioning appendage? A vacuum source?
And if i use this carb I can just block it off?
I seem to be able to blow a small bit of air through it.