Slice two onions; set aside. Chop remaining onions. In a large skillet, brown sausage together with chopped onions; drain. Add herb packet from the stuffing mix. Stir in raisins, pecans, celery, and seasonings; simmer for 10 minutes.
Add stuffing mixes and broth; mix well. Cook and stir for about 5 minutes. Season turkey inside and out with salt and pepper. Place reserved onions inside turkey. Add 6 to 7 cups stuffing. Place remaining stuffing in a greased 11/2-quart baking dish; cover and refrigerate. Skewer turkey openings; tie drumsticks together. Place on a rack in roasting pan. Bake, uncovered, at 325° for 4 to 41/2 hours or until a meat thermometer reads 185°, basting often with butter. When the turkey begins to brown, baste if needed and cover lightly with aluminum foil. Bake reserved stuffing, covered, for one hour; uncover and bake 10 minutes more.
Allow turkey to stand for 15 minutes before carving.