Clean and trim fat from rib slabs. Season the dry rib racks with a 2 to 1 mixture of chili powder and seasoning salt. Rub seasoning into ribs then wrap or place in air tight containers overnight in refrigerator.
Preheat your smoker or grill to 225 to 300 degrees F and fill woodbox with hickory wood. Cook the ribs slowly for about 4 hours, or until they are almost falling off the bone.
When ribs are done, cool at room temperature for 20 to 30 minutes. Wrap and refrigerate.
Preheat an oven, grill, or smoker to 225 degrees F. Reheat unwrapped ribs for 1 hour. Serve with barbecue sauce.