bbq, I have a 15 lb packer on right now. Been on about 7 hrs and internal temp is 151. Cooking on a UDS with grate temp about 235. Just a rule of thumb for me is to run it about 10 hrs and then make a decision to foil to speed up the cook to closer to 12 hrs. I also rest it wrapped in foil in a cooler for 2 -3 hrs before slicing. It will stay hot and sucks the moisture back into the meat. It gives you some leaway as each piece of meat can cook really different. Hope that helps. Good luck as let us know how it comes out bro.
my avatar swiped fatties from the plate....look how sorry he is.
NB Bandera with mods
Weber 22 .5" x 2, 26.75" x 1
UDS x 3
Created "The Great Spam Revelation of 2011."