The 4" transfer tube should be fine. I also think your chute is a bit odd but it should work fine. It should only burn as much charcoal as the air intake will allow. As far as your stack, it only needs to be the same size as your intake. With that being said, my intake is a 2" ball valve and I have 2- 2" stacks. It will run on just one though. Are you going to use a stoker or guru? The good thing about that huge ash box is you can burn a lot of wood down there. Keep the pics coming!
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