If you use a smaller pork shoulder (2-3 pounds) do you cut down the cooking time by half?

You want the meat to be at about 200º F for an hour to get the collagen to dissolve.

Thanks so much! Been in the oven for 3 hours and it's close to done. YUM!

I don't know if you could cut it by half -- but you could certainly cut it. They key to the taste, though, is the long, slow cooking. Your best bet for knowing when it's done is to stick a fork in it and twist....if the meat comes away in shreds, it's ready.