Fit piecrust into a 9-inch deep-dish pie plate according to package directions; fold edges under, and crimp.
Sprinkle pecans and chocolate evenly onto bottom of piecrust; set aside.
Combine corn syrup and next 3 ingredients in a large saucepan, and bring to a boil over medium heat. Cook, stirring constantly, 3 minutes. Remove from heat.
Whisk together eggs and next 4 ingredients. Gradually whisk about one-fourth hot mixture into egg mixture; add to remaining hot mixture, whisking constantly. Pour filling into prepared piecrust.
Bake at 325° for 55 minutes or until set; cool on wire rack.