390 double pumper vacuum

plug vacuum advance into manifold and use one of these to smooth it

FSE VACUUM ADVANCE ANTI PULSE IGNITION DISTRIBUTOR VALVE APV001 | eBay

allows a barb into manifold vacuum of a size greater than a normal ported vacuum take off to be used.

basically a tube with a bunch of small orifices in it designed to damp any vacuum fluctuations


OEM kit on 2 liter alfa and fiat where it was used to allow vacuum advance to be driven off 1 cylinder when equipped with weber or dellorto dcoe/idf drla/dhla

still available 40 years later due to usefulness, when repurposed for implementing Fuel Injection ECU with MAP sensor

i.e used all over the place for vacuum signal smoothing

got a lathe and some jet drills you could probably make one

only ever seen APV001 i.e Anti pulse valve 1, never seen a 2 so presume they got it right first time :)


Dave