I now believe the following to be wrong.

Second theory.
Whomever wrote the tech bulletin looked up the part number for the silencer and went to 9-41-1 and then saw the word silencer directly over the description of w/3-2 bbl carbs and grabbed the part number 3420039. He should have used the correct part number for the Silencer Package, tappet chamber 1879747.

If I understand, you're suggesting the 'silencer package' was a superduper valley pan cover? That would make sense. Didn't JD mention some 'insulation' under the manifold?
Not questioning, just asking.
More ebay keyword fodder.

I show the silencer package in all the parts books from 1966-1974. I don't have any parts books before or after this date range. BB only.

Here is a picture from the 1973 parts book. The silencer package is #8.

Snoopy, did you put the "silencer package" text into that illustration? I was reading an article on the Hemi engine and at one point it stated that "hydraulic tappets were added to significantly reduce noise....." almost makes me think that besides eliminating the need for periodic adjustments the hydraulic tappets were also used to reduce noise.......

I don't know (I'm checking) if the EPA's sound test procedure was in place back in the late '60's but it is a test that takes in ALL noise that exists during a "drive-by" the sound meter at 50 feet at what would be "full throttle in second gear" and this registers ALL noise, including air intake noise, exhaust noise, tire noise, EVERYTHING even valve tappet noise. Hence the lack of exhaust tips, and dual or single snorkel air filter covers for California in 1969 even on the HP engines. So is this considered part of a "silencer package" just as they consider day/night mirrors part of the "Standard Safety Features" Were there different levels of "silencer packages"? What about underhood insulation and undercoating, those were a noise silencer (not rust proofing, as most think).

Just kicking things around a little, no offense intended.


MikeR

I added the wording to help point it out. It is called out on the next page of the parts book.
The illustration of the silencer package isn't to scale and although it has been available since at least 1966, it didn't appear in the illustrated section until 1972. I think you will find it on most BB C-Bodies. My thinking is that it was added to the A12 cars to cut down noise from the engine compartment due to the fiberglass hood and lack of under hood insulation. According to the 1985 price list, it sold retail for $4.49. It could be an insulation blanket that sits on top of the valley pan.

Notice in the product bulletin that it lists a qty of 1 and not 16.

Here is the second page with the index for the picture with the Silencer (8).

Third and probably the most accurate theory on the Silencer Package.

The guy that put together the Product Bulletin made two mistakes. The first one was in the nomenclature, it should have been valve tappet (lifter) and not Silencer Package. The second mistake was in the quantity, it should have been 16 and not one. The only thing he got right was the part number.
The reason I believe this to be the case, is that the valve tappet (lifter) was only used on the A12 cars in 69 and the 6 BBL cars in 70-71 and was therefore peculiar to those cars. It would have been included in the Product Bulletin.
In which case there was no Silencer Package on the A12 cars.

Silencer package or no silencer package, hasn't this been previously resolved on this Forum?

What was the conclusion?