Preheat oven to 350 degrees.
Bake pie shells for 10 minutes; cool.
In bottom of each baked pie shell, sprinkle 1 c chocolate chips and 3/4 cup chopped walnuts.
Combine butter, sugar, corn syrup, eggs, and bourbon.
Divide mixture among the pie shells.
Bake 10 minutes.
Decrease oven to 325 degrees and bake 30 to 35 minutes more or until center does not move and knife comes out clean.
Let cool at room temperature.