I'm smoking 2 3.5 pound chickens for the first time. I am planning on using the beer can style. I've rubbed them down with a chipotle rub. If I keep a temp of 230 - 250. How long will it take? Will it be roughly 3 or 4 hours? I am also using a digital probe and plan on pulling them out as soon as the internal temp is between 165 - 170.