i also have the double vacuum advance on mine with a weber 34dgec. hook the vacuum line to the bottom nipple and plug the top. itll work just fine.i removed all the other vacuum lines and compnents with the exception of this line from the carb baseplate to the dis. youll have to plug the other ports with bolts or plugs. oh, when you install the weber, you`ll see two holes in the intake where the carb goes. tap and plug these holes as not doing so will cause the coolant to wear through the base gasket for the carb and leak down into the intake causing lean mixture and overheating over time.where in tx you at?