who knows about Marelli Digiplex advance ?

I have an 82 308, and I am reconstructing all the missing plumbing....

Regarding the vacuum spark advance, does the marelli digiplex ignition unit need to be connected directly to the intake manifold, so the unit sees max vacuum at idle, or does the ignition unit need to be connected to a vacuum port upstream from the throttle plate, so it sees max vacuum at max throttle plate opening (ie like a typical vacuum advance distributor) ??