Smoking 3 nine pound shoulders

Nothing will really change on your smoking, as long as your grate temp variances are acceptable for running a bit heavier load with a larger foot-print on the grate...but that's getting down to the really finicky nuances of smoking. If you've done 2 at a time, 3 won't be change what you do, especially when finishing in the "O"...you can probe for I/T and poke around inside a bit for tenderness before resting, but you already know that. If you know you have hot/cold spots on your grates thjat you can't avoid with having 3 on the grate, you can always rotate the positions of the meat your grate a couple times before foiling (or whatever you place it in to transfer out of the smoker...that even out the cooking rates of each piece so they're all finished closer together. That's about it.

Enjoy the smoke, and have a safe and fun Independence Day celebration!!!

Eric

Pork shoulders won't take that long. You would have been fine getting a good nite's sleep, then getting the fire started at say 0500-0530, take 45-60 minutes to get chamber temps stabilized at 265-285F, and then get the protein on. You'd have plenty of time to hit an IT of 200F on the smoker, take them out and wrap em in foil, then towels, and let em sit in an ice chest until dinner.

How did your above schedule work for you? Long night, right?!!!