I’m planning to cook four pork shoulders, about 30 +/- lb s, for a coed baby shower for my daughter, with 40 people invited. I’ve never cooked four at a time, only two, which averaged about 15-16 hours per cook at 225. Will cooking four add any appreciable time to the cook, and if so, about how many hours? I want to make sure they are done, rested, pulled and cleaned up before people start showing up.