I might recommend a large heavy plate a few inches above the inlet in the cook chamber. This will help to spread out the heat and provide some nice radiant heat as well. Wouldn’t go thinner than 0.25 on it. I run one in my warmer box (directly above the firebox on mine) and it works great. I sized it to leave 2 inches around all the sides for heat to rise.
Thanks guys dirtytires there will be a 1/4 under the lower tube with a 2.00 opening to the back off the CC . So with my false wall in place I will have a build in water pan. I was thinking something under the plate that makes the top of the firebox maybe I don't need anything yet no sure kinda winging it as I go.