I am getting ready to put the stack on a small reverse flow I am building, and was looking for some input on the height of the pipe from the cooking grate. Should it be at the top of cooking chamber, or closer to the cooking grate?
Alot of folks say it doesn't matter with a reverse flow. I placed mine at grate level and it works great. I think it helps retain the heat that would otherwise be lost if the stack was placed higher. I'm no expert but just one opinion. Happy smoking!
If you decide to not extend the pipe down into the chamber you can add a mod that is removable. I have a rolled piece of aluminium flashing up in my stack. It can be easily adjusted up and down or removed for cleaning.....
And to add to what Boykjo said, its adjustable so you can control the heat/smoke to suit your method of cooking, for example you might want the exhaust pipe slightly higher than the grates for an all wood smoke and lower the exhaust pipe closer to the grates for charcoal and Lump.
Thanks for the advice. I endeded up welding two peices of 2x4 rectangle tube together side by side so the stack ended up being 2 in deep by 8 in wide. One side I left high in the cook chamber and the other side I brought close to the bottom grate, both sidesof the stack with a seperate damper plate on top.