Preheat the oven to 350 degrees F (175 degrees C). Grease a 9x13 inch baking dish.
Break bread into pieces, and place into a large bowl. Pour milk over bread, and crush with your hands until well blended. Stir in 3 eggs, 2 cups sweetener, vanilla, 3 tablespoons margarine, and raisins until evenly mixed. Transfer to the prepared pan.
Bake for 45 to 60 minutes in the preheated oven, or until very firm.
To make the sauce: In a medium bowl, cream together 1 cup sweetener and 1 egg until smooth. Gradually mix in the melted margarine, and continue stirring to dissolve sweetener. If the sauce is difficult to blend, it may be heated gently, but be careful not to curdle the egg. Gradually stir in whiskey which should make the sauce creamy smooth.
To serve: Allow pudding to cool completely, then cut into cubes, and place into individual heat-proof serving dishes. Pour sauce over, and heat under the broiler until golden, about 3 minutes.