Morning, afternoon or good evening. A bit of back history from me, live in England, vehicle mechanic and love making things. I've made 3 santa Maria style pits, a 6ft open bbq for a local pub and now I'm on to the next project, a offset smoker. So far I have a 17"X54" compressor tank, I'm not sure on the thickness yet but its from the 80s so I'm going with fairly think, and I've made the fire box 18x18x20 from 4mm sheet. I've used the various calculators and come up with the numbers for the vents/stack size etc. But what I cant decide on is to make it reverse or regular any input would be much appreciated