pork shoulder roast roasting question
Pork shoulders should be cooked low and slow, which is great because it gives you quite a bit of wiggle room. I'd recommend 12  hours at 275 with a lid on each roasting pan. I'd also recommend searing them on high heat before roasting in the oven.

Here's some anecdotal evidence to back me up:http://eggheadforum.com/discussion/1143833/how-long-to-cook-two-10-pound-pork-butt