Not real into per pound figures. If it is typical, ~5.5 lbs, and you trim and tie it, it will take 45-75 minutes to get to 120-135? at a cooktemp of 225-250. How long, specifically, will depend on actual cooktemp and your target internal. Then, do a finishing sear by carefully removing the grate with the meat on it, then the cooker's center section, and next placing the meat (on its grate) directly over the coals to sear it on all sides. Rest 12 min or so, tented; serve.