Well, you could've waited on the clamps till ya find out if you have a sprung door. As Sonny Moberg explained, the pipe is rolled differently. When the door is cut out, if there's tension in the pipe, then the door springs.
I used the
Lava Lock RTV silicon, what I had was red in color, but they make it in clear and black, wish I'd used black. Lay a bead on the cook chamber, all the way around, cover with plastic wrap, and then close the lid.
I bought tuning plates from Old Country, but honestly, they're more trouble than worth. Adjusting those plates just adds another variable. I've ran biscuit tests with them and without them, and really, moving the meats around has worked better for me. And after doing multiple biscuit tests, I quit worrying about end-to-end temps because that does not really tell the story of what's happening in cook chamber.
I always have the stack wide open, never close it. I used tin snips to cut around the damper. IDK why Old Country put such a short stack on this smoker, maybe it lowered shipping costs , IDK ?