Preheat the oven to 375.

Scrub the potatoes and pierce the skins with a fork. Bake the potatoes for 1 hour, or until tender. Cut a 1-inch lengthwise strip from the top of each potato. Carefully scoop the pulp from the potato shell and place in a large bowl. Beat in the orange juice, butter, and salt until fluffy. Stir in the pineapple, then use the mixture to stuff the potato shells. Sprinkle with pecans, if desired. Bake for 15-20 minutes, or until completely warmed through.