i imagine the difference is minimal.
anyhow, i find the idea of this to be utterly fantastic and mad in the way that cooking three birds in one should be, so here's the recipe:
"The Turducken will need to cook for 12 or 13 hours at 190 degrees F so begin preparation well in advance.
20-25 lb whole turkey
4-5 lb whole duckling
3-4 lb whole chicken (or use a larger chicken and place the duckling inside it)
corn bread dressing
large roasting pan and rack
cotton string and cheese cloth
Place the cleaned turkey, breast side down, on a flat surface. Cut through the skin along the length of the spine. Using the tip of a knife and starting from neck end, gently separate meat from rib cage on one side. Toward neck end, cut through meat to expose shoulder blade; cut meat away from and around the bone, severing bone at the joint to remove shoulder blade. Disjoint wing between second and third joints. Leave the wing bones and keep the wing attached to the meat.
Continue separating meat from frame, heading toward the thighbone and being careful to keep the "oyster" (pocket of meat on back) attached to skin, rather than leaving with bone. Cut through ball-and-socket joint to release thighbone from carcass (bird will be open on one side, exposing bones left to deal with). Keep the leg attached to the meat.
Repeat boning procedure on the other side of the bird. Carefully remove carcass and reserve for making stock. You should end up with a flat boneless (except for wings and legs) turkey with the skin intact in one large piece. Cover the boned turkey and set aside (or chill).
Repeat the process on the duckling and chicken, but cut off the first two joints of wings, and debone both stumps of wings and leg drumsticks (cut through flesh at thinnest point and trim around these bones with a knife until they can be removed). Trim excess skin and fat from necks of birds. If it is your first time deboning a fowl, it is advisable to practice first on the chicken rather than the turkey. Both the chicken and duck will be stuffed inside the turkey and need not be kept "perfectly" intact. Make stock from the chicken carcass.
Prepare seasoning mix and set aside:
3 tablespoons salt
1-2 tbsp. paprika
1-2 tbsp. garlic powder
1-2 tbsp. pepper
1-2 tsp. dried thyme
Prepare sausage stuffing: Melt butter in large skillet over high heat. Add 3 cups onions and 1-1/2 cups celery. Saute until onions are dark brown but not burned, about 10 to 12 minutes. Add 2 lbs sausage (we prefer spicy Italian sausage) to the skillet and cook about 5 minutes or until the meat is browned, stirring frequently. Add paprika (3 tbsp.) and minced garlic (3 tbsp.) and cook about 3 minutes over medium heat, stirring occasionally. Stir in 3 cups of chicken stock and bring to simmer. Continue cooking until water evaporates and oil rises to top, about 10 minutes. Stir in 2 cups toasted bread crumbs and mix well. Add more bread crumbs if mixture is too moist.
Prepare a similar amount of another stuffing such as corn bread stuffing.
At least 13 to 14 hours before dinner, assemble the Turducken.
Spread the turkey, skin down, on flat surface, exposing as much meat as possible. Rub 3 tablespoons of seasoning mix evenly on meat. Spread sausage stuffing over the turkey in an even layer approximately 3/4 inch thick.
Place duck, skin down, on top of stuffing. Season exposed duck meat with about 1 tbsp. of seasoning mix. Spread corn bread stuffing in an even layer (about 1/2 inch thick) over the duck.
Arrange the chicken, skin down, evenly on top of corn bread stuffing. Season chicken meat with seasoning mix. Spread remainder of sausage and/or corn bread stuffing on top of chicken. The assemblage will look something like this.
With another person's help, carefully lift the sides of the layered birds, folding the sides of the turkey together. Have a helper hold the bird while sewing the opening down the back of the turkey together using cotton thread. The bird may not close perfectly, and a strip of cheese cloth can be used to help close the "crack" in the back of the turkey so stuffing will not leak out when the bird is turned over.
Since the turducken has no skeleton, it must be trussed up or it may fall apart in cooking. Tie cotton string around the bird, widthwise, every inch or so along the bird's length. Turn the bird over and place in a roasting rack inside a large roasting pan so it is oriented breast side up and looks like a "normal" turkey. Tie the legs together just above the tip bones.
Heat oven to exactly 190 degrees F. Temperature control is critical since the turducken is so massive that it has to be cooked very slowly at a low temperature. Using an oven thermometer is highly recommended.
Place the bird in the center of the oven and bake until a meat thermometer inserted through to center reads 165 degrees, about 12 to 13 hours. There will be no need to baste, but accumulated drippings will have to be removed from the pan every few hours so that the lower portion does not deep fry in the hot oil. Remove the turducken from the oven and let cool in the pan for an hour before serving. Make gravy according to your favorite recipe.
To serve cut bird in half lengthwise. Carve crosswise so each slice reveals all 3 meats and dressings. Will make 15 to 25 servings."