Preheat the oven to 375°. Line the bottom of the oven with foil in case of spills. Divide the pecans evenly between the pie shells. In a large bowl, combine the eggs, egg yolks, vanilla and salt. Whisk in the brown sugar and butter until smooth. Whisk in the corn syrup. Pour the filling over the pecans, pressing them down with a spoon to coat them with the syrup. Bake in the center of the oven for 15 minutes.