So, area wise, I have the same amount of air intake, but less exhaust. My 8 1/2" holes at the top are half of what you run, and if I ran 3 rods for a full load of meat, the holes are obstructed even more. One of my barrels has a 2 threaded plugs in the top, removing one would make for an easy test.
I also need to get the bigger fire basket done, so I can run it with a full load and see what happens.
What is your "usual" air intake configuration for chicken, and what temp do you try to run at?
Thanks for the help! I'm sure all these questions have been asked and answered a hundred times before, so thanks for your patience.