What's missing here?

Hi,
I'm just in the process of re-building my 1984 3.5 v8 after a camshaft change and I've got small vacuum pipe with nothing connected to it. The pipe is on the right hand carb (stromberg CD 175) at the junction between the carb and the inlet manifold. Can anyone tell me where the other end of the pipe should go?

Thanks

Matt

vacuum advance to the dizzy?

vac unit on the maifold then to the dissy brass cylinder