Holley Carb- What Is It

[raoul.duke]

What does this hose do?

[Livrat]

That is for what is called the choke stove.. it circulated hot air from either the intake manifold.. (see pic) or pulled air directly from the exhaust manifold to sense whether the engine was cold or warm thus opening or closing the choke.. It appears your carb has the electric conversion so it may be fine as is...
If you would like to connect it you can get the universal kit from Summit or Jegs which you clamp to your exhaust manifold or headers