Where's this "folder" for cocktail shakers info.? I've always been curious about more on them. I still have all four (and they add a ton of weight to the front fenders).
There are a few "cocktail shakers" / "vibration dampener's" discussions here about their purpose, function, and various configurations depending on the year and Camaro vs Firebird interchangeability. Functionally, one of the best may be 4 Corner Cylinders which includes an article Jeff had where the author cut one to expose the insides. I recently found them in the '68 Camaro Assembly Manual. It confirms that they (4) are filled with 1.25 gal of auto trans fluid.