I have a 2010 Sierra, 2wd, 6.2 l, 6 speed, 3.72 rear I believe with locking differential. They call it an "extreme towing package" crew cab. I now have 40,000 miles on it and am a bit annoyed at the kind of rough ride even with the Wrangler tires pressure 35F-40R for towing. Is there a milder rebound shock I could install for a smoother ride. I hate the loudness on asphalt with these tires but they have better than 1/2 their tread left and I just had them rotated. I think Michelin M/S tire would be quieter at highway speed. I'm not getting the trade fever, at 72 this is my last vehicle and boat. What would you suggest?