Redman; definitely recommend you use high-temp silicone (permatex & can get @ any auto part store) & new muffler clamps (get @ HD for ~$12/ea). I've heard stories of systems having leaks & getting/using these items will help prevent any leakage problems.
Also, don't over torque the clamps - use HD's recommendations. I'd list the #'s, but still stuck @ work for a bit. Sure someone will chime-in w/exhaust clamp torque specs.
Good luck!