I got a 500 gallon propane tank, this will be my first build. I would like to do reverse flo but need some advise. Say my firebox is on the left, I weld the plate in 4 inches below the bottom rack, the opening of the plate would be on the right? Then my stack would be on the left? So the smoke has to travel undernieth the plate under the whole length, then into the smoke chamber then all the way across to the left out the stack, am I right? Also, what would be the dimensions of the firebox, Im too confused with the chart. Any other suggestions?