Do you reall you really need to use a ball valve? What about just putting some holes at the bottem that can be adjusted for air flow work just as good if not better?
Another question is, can you create an opening on the side of the barrell to add fuel if you use some type of gasket to ensure that it's air tight? If that's not a good idea how do you add fuel to the fire when you are on a long burn? Do you have to take out the meat to get to the firebox to add fuel?
Smoke a fatty, Eat a Fatty, $hit a Fatty...LOL