Slow roast pulled pork. How long to cook? Need for tomorrow.

If you have time, I would cook it at 225 for about 9 hours, butt if your in a pinch, 300 will work. Shoot for the internal temp to hit 190+ and insert a fork and twist. If the meat pulls apart easily, the fat has melted ad it's ready to impress. If you don't do the fork test, you could end up with tough fatty pieces. I usually do a good rub with olive oil before cooking and just leave it after that. Another idea would be to cook it on your grill, placing the meat on a foil tray with only the outside burners going on low/med. that way you could add some smoke chips too.

When I make a Boston butt, I generally do a 3-4 lb roast. In the Dutch oven after searing, It usually takes about three to four hours to get to the completely meltingly tender stage. I would check after two hours, but allow yourself at least four. You can do it stovetop on med-low or in a 300 degree oven. Good luck!

I'm sure someone more expert will weigh in, but I'd count on 1 hr per pound and check it every few hours. Pulled pork is forgiving as long as you don't undercook it - so I'd overestimate cooking time and let it rest if it turns out not to need quite so much time.