Heat the oven to 425°F and prick each potato several times with a fork.
Rub the potatoes with the oil and 3/4 teaspoon salt and set them directly on the oven rack.
Bake until the skins are crisp and a skewer meets no resistance in the centers, 55 to 65 minutes.
Warm the pulled pork and barbecue sauce together in a covered saucepan over medium-low heat.
Split the potatoes, squeeze the ends to open them and fluff the centers with a fork.
Season the potato flesh with the remaining salt and black pepper, then fill with hot pork.
Top with cheddar, sour cream and scallions and serve while the skins are still crisp.