I think it may depend on the thickness and quantity of the ribs. I got mine from Sam's and they were pretty thick. I ended up going 3-2-1 and they turned out great. I had read all sorts of different times, but 3-2-1 worked for me, I smoked 6 racks today. Allow some prep time in your calculation, 3-2-1 is more than 6 hours total time by the time you pull them, wrap them in foil, pull them again, cover them with BBQ sauce, and put them back. I had some hungry kids waiting a little longer due to not including that, especially with 6 racks.