Petcock and Vacuum What goes where?

1985 Yamaha XJ700 Maxim X - The carbs have three lower, back spigots. I'm assuming they are all for vent holes?

On the left front I have a spigot on the second carb in. Does the gas go here?

I've heard that if I have a vacuum, I should put the hose to the second intake hose on the engine from the left? Is that correct?

Thanks for the help. I'm this close from starting it up after rebuilding it.

 

It matters not which Manifold Vacuum use choose to supply Vacuum to the Petcock.

The Fuel Hose goes from the Fuel Tap to the "T" joining the Common Fuel gallery between the #1 & #2 Carbs.

::: Tip :::

Use New Vacuum and Fuel Line.
Loop some slack to be able to leave the Tank connected if you have to raise it up for Tuning.
Use Right Angle UNIONS to Install a Inline Filter --> Vertically, ... at the rear of the Rack.
Paint Miniature Hose Clamps with BLACK Nail Polish to have them disappear.
Briggs & Stratton Aux. SHUT-OFF for Insurance.