Ok gang. I am going to try to help out here as well. I have made a few easy mods to my
CharGriller with SFB.
I have made only 2. The first one was to buy a piece of the aluminum flexible tubing for a drier vent and a hose clamp. I cut it, with a sharp pocket knife, and slid it over the smoke stack. Then formed it to the shape of the lid until it was right at the grate. The other mod was I got a piece of expanded metal and placed it on top of the cooking rack inside the side fire box. That allowed me to have LOTS of room for the charcoal dust to accumulate without smothering the lit coals. If the coals are in the bottom of the side fire box grate, you only have abt 1" of space for all of the dust to build up, then it starts to smother the lit coals and you loose temp.
Don't use the thermometer in the lid. Go to WallyWorld, or any other store and pick up yourself an oven thermometer and place it on the grate. That will tell you the temp where you are cooking the meat etc., and not the upper section of the lid.
This is all I have done, and it works great now. I have place an aluminum pan of hot water next to the inlet of the main chamber before I done the mods. Now I don't.
Using the side fire box only, it is hard to get temps much over 250ish without using a lot of wood. And by using the expanded metal up higher, the temp are hotter, and so the paint is burned off in places on the SFB, so if you do this mod, just spray it with cooking oil after it cools down, and it will keep the rust at bay.
Bill