The nice thing is that even if you get them done early you can take them off the smoker add another layer or two of foil and then wrap them in towels and rest them for at least two hours is necessary. And you'll be shocked at how hot they still will be when you take them out and begin to pull them.

The key in pork butt is not so much time but tenderness. I prefer none in because the bone actually tells you when they are done, because it will start moving is way out of the meat. When I can grab it and it feels like it works come out easily with just a tiny bit of effort, it's done.

For bone out. Use a fork and stick it into the meat a little ways and then twist. If it starts to pull real easily like that then you know that the ribbons of fat have rendered and you will have really tender pork. I've got to the point though where all I have to do is shove in the meat probe and if it slides in with li
ttle effort I also know that the pork is done.

One other thing. If you wrap and you leave it wrapped until they're done, the only real issue is is that it will soften the bark. So if you want to crispy bark, take the foil off the last couple hours to firm the bark back up.