Wrap each potato in a piece of aluminum foil; place potatoes on a baking sheet.
Bake potatoes at 425° for 45 minutes or until tender.
Cut a 4- x 2-inch strip from top of each baked potato. Carefully scoop out pulp into a large bowl, leaving 8 shells intact; set aside about 2 cups of pulp for another use. (See "Cook's Notes.")
Mash together remaining potato pulp, cream cheese, and next 5 ingredients; stir in pork. Spoon mixture evenly into shells; top evenly with Cheddar cheese and chives. Place on a lightly greased baking sheet.
Bake at 375° for 20 to 25 minutes or until thoroughly heated.