It looks like someone tried to make a PVC by sucking fumes out of the valve cover into the vacuum port.
The fumes should be sucked from the crank case, and a PCV valve should be used. If you have a road draft tube at the crank case, that`s good to go.
Take the brass elbow and connect it to your wipers.
The port at the intake (where the wipers should be connected) delivers most vacuum at idle and almost non at hig rpm. You need high vaccum at high rpm for the spark advance.
So the spark advance must be connectet to the carb.
There is a port at the back (passenger) side.
Hope that helps.
Frank
