You will probably want to take them higher than 160, I would hazard a guess they would be closer to 190-195 by the time your done but I don't know I have never took meat temp of ribs I always go by time and how they look, bend and wiggly bones. If it is your first rib smoke try the 3-2-1 method for spares or 2-2-1 for baby backs, pretty fool proof way to start out. That is 3 hours unfoiled in smoke, 2 hours in foil with a bit of foiling juice, and 1 hour unfoiled to firm back up. My wife likes them fall off the bone and I haven't had a complaint about this method yet, and as you do a few more you can adjust the times in and out of foil to suit your preference. Just search 3-2-1 method here lots of great advice and recipes.