I need ideas... My volume in the fire box is about 40% over recommend . On my first smoke last Sunday I went through about 50 pounds of charcoal/lump combo. I contribute this to the oversize.. It was a 9hr plus smoke. If I bring the FBI size down to recommend will this really reduce fuel that much? My ideas range from cutting box ( I really don't want to do that), adding fire brick for volume or could I weld on a plate to form like a triangle to refuse volume? Fire brick is $.