Having some modifications done on my pit. Thinking about making a firebox insulated. I have a regular off set smoker. Cooking chamber is 9ft long, 30" diameter, 3\8 thick. I had 3 smalls doors converted into 2 large doors, and another shelf installed, to increase cooking compacity. On firebox, put another slide baffle or air controller on rt and lt side of box. Hopefully being able to tune it better for those cold days, or when I need more air flow. Suggestions, should I make it a insulated fire box, to decrease fuel comsumption, and if so how should I go about doing it. Or ideas and best products to use. Need to try and explain to my welder, as he never made a bbq pit.