I built a 26 gallon rf a few years ago just to cook Briskit at contests, out of stuff lying around, I had a 26 gallon tank, a chargriller sidebox And 2 14x24 chrome wire shelves. it ran ok,maintained 225-250 no problem, but woulden't go any higher. At that time I had never seen a build calculater to run specs. I ran daves calculater and openings were right, stack has a damper. I did new lower and upper intakes on the firebox, and tested it yesterday, 50 degrees,wet,breezy, put up a popup, and smoked 1/2 a turkey Breast , A small Pork Roast, And about 5 lbs of country ribs. With very little adjusting it would now run up to 350 if wanted, ran a constant 225 I like to cook at, temps were within 5 degrees front to rear. This smoker has a half moon baffle between the fb and cc, and a sliding plate to adjust the space at the end of the rf plate. WE never had to touch those extra adjustment points. The legs telescope 12 inches, the front shelf folds down, and the stack lifts off, So it wiuld fit under the cap of a mazda pickup. The difference after making Daves mods were like night and day.Thanks Dave!! Four hour cook on 5 chimneys of charcoal on a wet dreary day!!