edelbrock c355 vacuum

Where do I tap manifold vacuum on a Edelbrock C355 manifold.
A picture would be great.

 

Everything was polished off, so I don't know who's intake this is; but I tapped into the common area on the back of the intake under the rear carb. 1/8" street tee and barbed fittings for the trans and advance.

 

There should be a boss for that on the drivers side between the front and center carb.

 

Here's a pic from the net.