What kind of smoker are you using? Temperature should be about around 240-250Â° F. When it's done it more a matter of internal temperatures than time. Brisket can plateau which means they like to hold at some temperature arounf 150Â° F or so and stay there for several hours. You can't usualy set your watch by them.
If you want to slice it smoke till about 190 - 200Â° F.
If you want to pull it smoke till about 200 - 205Â° F
Wrap it in foil then in towels to let it rest in a cooler for about an hour. It'll get nice and juicy!
Really nice smoker! Did you make it? It's a beauty! You shouldn't have any trouble smoking a brisket in that one.
The "general rule of thumb" is 1.5 hours per pound but like I said sometimes they hit a plateau that can last for several hours all you can do is wait it out! It's worth it though. Just don't be worried or surprised if it doesn't finish "on time." AND Use a thermometer!
Thanks for the tips and the comments on the pit. I wish I could tell you I made the pit, but I can not take the credit. A guy outside of Houston makes them in his free time and sells them...Perhaps I will take better pics soon...