Think this over ... the reason for the extended stack is this.. Till I can build a Roasting shed, I'm roasting on my front porch.
What I found was without any stack the rising temp was being adjusted by the cooling breeze. So, my whole reason for the stack is to keep the air temp as close to what it is without any cooling function by the open stack.
I also, being a rule breaker, have oped to run this with 2.5#.. (I was not pleased with my left over bean remainders, if I were to run the 2.8#.)
So a touch less weight and a bit more down pressure and my roasts have been quite nice. But its all experiments for me.
After cleaning and my stack, i'm pretty pleased....