We are cooking two 6-7 pound bone-in, smoked (not pre-cooked) butt portions. They need to be cooked at 250 because there's only one oven. The powers-that-be seem to have decided that 325 is the magic temperature for ham, and after googling and asking my grandma, I'm coming up empty. If I try to determine this mathematically, using oven temperature*time as an analog for Joules of heat delivered, for a 7-pound ham, I come up with about 4 hours and 20 minutes. But I'm not sure if this is a correct way to figure it out. Can anyone help?