Preheat oven to 325 degrees. Set aside 16 pecan halves for garnish; coarsely chop remaining pecans. Stir together eggs, sugar, corn syrup, butter, vanilla, and salt in a medium bowl until well combined. Stir in chopped pecans, and pour mixture into prepared piecrust, spreading evenly. Garnish edges with remaining pecan halves.
Place dish on a rimmed baking sheet, and bake, rotating halfway through, until filling is just set and crust is golden brown, about 90 minutes. (Tent with foil if nuts are getting too dark.) Transfer to a wire rack, and let cool completely. (Pie can be stored at room temperature for up to 1 day.)