Mo-Dave was talking about lowering the exhaust stack down to the grate level so you won't lose heat as fast.
Here is a link that will be useful for you.
In the 11th post shows you what to do.
Team: Pyle's BBQ; Yoder YS640; Good-One "Trail Boss" 60T; Weber Kettle w/rotisserie ring; Big A$$ Rotisserie; Weber OTS; New Braunfels offset smoker.
Saddles BBQ Bistro