Offy flathead intake, what is this hole for?

8BA flathead with Offy intake with Holley 4 barrel, there is a small hole on the drivers side in the casting as seen below, it appears to exist on the Edelbrock 4 barrel manfolds as well. I searched but could not find any info. I could just be a dumbass but what purpose does it serve? Should it be ran to something, plugged or is it just a vent hole of some sorts? Air appears to be coming out of it and not being drawn into it. Engine runs great other than the annoying hissing sound eminating from said hole. Thanks in advance for any help.

 

So I guess we are assuming it is not a vacuum port?

 

heat riser for automatic choke

 

You know....I wonder if it is a port for a heated choke? It is in the center of the intake right where the heat riser is in the block.

 

Might just be the picture, but it looks like the manifold is cracked around that runner or boss.

 

I was thinking the same thing Dyce.

 

Heat riser was one thing that crossed my mind as well, makes sense since what looks like a crack is where the paint has flaked off the manifold exposing the bare aluminum underneath. I'm assuming that if I don't need the heat riser (carb has electric choke) I can plug the bitch?

 

Yes, seal it off.

 

It is indeed a hole into the exhaust crossover.

 

Thanks guys