Blend flour and salt in processor 10 seconds. Add butter; cut in using on/off turns until mixture resembles coarse meal. Add 4 tablespoons ice water; blend just until moist clumps form, adding more ice water by teaspoonfuls if mixture is dry. Gather dough into ball; flatten into disk. Wrap in plastic; chill 1 hour. (Can be made 2 days ahead. Keep chilled. Soften slightly at room temperature before rolling out.) Preheat oven to 350°F. Coarsely chop 2 cups pecans and reserve. Spread 1 cup pecans on rimmed baking sheet. Toast in oven until nuts are aromatic and darker in color, about 12 minutes. Cool, then grind nuts finely in processor. Maintain oven temperature. Roll out crust on lightly floured surface to 13-inch round (crust will be thin). Transfer crust to 10-inch-diameter pie dish. Fold overhang under, forming high-standing rim. Crimp edges decoratively. Freeze crust 20 minutes. Whisk eggs in large bowl until frothy. Add sugar, corn syrup, melted butter, vanilla, salt, and ground toasted pecans; whisk until blended. Mix in chopped pecans. Pour filling into crust. Bake pie until crust is golden and filling is puffed and set (center may still move when dish is shaken), about 1 hour 10 minutes. Transfer to rack and cool at least 3 hours. (Can be prepared 8 hours ahead. Let stand at room temperature.) Cut pie into wedges and serve slightly warm or at room temperature with whipped cream.