Preheat the grill to 300 degrees and lightly oil or spray the grates. Maintain this grill temp during cooking process.
Add dry spice rub ingredients to a small bowl then whisk to combine well. Set aside
Remove silver skin from the back of the ribs. Using a small paring knife, slide the tip of it under one corner of the back of the ribs under the membrane. Once you get it started, use paper towel (for a better grip) and pull it back separating it from the ribs until the whole silver skin is removed.
Generously seas ribs on all sides then use your fingers to give it a good rub. Cover seasoned ribs with plastic wrap and and let it sit for 15 minutes.
Tear off a large sheet of aluminum foil (enough so the ribs can sit in the center of it and the foil will fold around it. Remove plastic wrap and place ribs on the center of the sheet of aluminum foil. Wrap it right around the ribs.
Place foil packet on the grill bone side down. Grill 45-60 minutes turning the wrapped ribs over a couple of times so they cook evenly (be careful not to pierce the foil). I recommend 45 minutes for St. Louis style – full 60 minutes for meatier baby back ribs.
Remove ribs from the grill and take them out of the foil, discarding the liquid. Place the ribs onto the grill grates meat side down and continue cooking 15 minutes, again turning them for even cooking.
After 15 minutes, increase grill to 400 degrees then brush your favorite bbq sauce. Grill another 2-3 minutes until the sauce is glazed then remove from the grill onto a platter or cutting board.
Let the rack of ribs rest 5 minutes then use a sharp knife to slice into 2-3 rib sections.