Combine sugar, eggs, and salt in a medium mixing bowl; beat until light and lemon colored. Combine butter and flour, stirring until well blended. Add flour mixture to egg mixture; beat well. Gradually add milk, beating until smooth and creamy. Fold in 1 cup coconut.
Pour mixture into unbaked pastry shell. Sprinkle remaining 1/2 cup coconut over top. Bake at 325° for 1 hour and 10 minutes or until a knife inserted in center comes out clean. Cool slightly before serving.