Ragu your buddy is correct. I can't find documentation but if memory serves GM had a big retrofit/recall/tech bulletin type of thing going on in the early/mid-70's where these little filters were added to many cars not originally equipped, and they came factory equipped from mid-70's all the way thru much of the 90's or until fuel injection took over. I believe maintenance requirement in the bulletin stated the filter should be changed annually. They actually are not so much a filter, but a little charcoal canister, and they are supposed to be installed vertical to work properly and absorb stray fumes. Not so much a problem when engine is running and sucking everything inward, but when vehicle is parked and carb just sits there evaporating fumes some will travel up the vacuum line and seep into the booster, supposedly shortening its lifespan and/or MAYBE an emissions/EPA thing that started with the smog era. These were never on our FGF's but could easily be added if you really feel the need. I do not, but seeing that you're suffering multiple failures it may not be a bad idea...
