Yes, another muffler thread. At least it's not an "exhaust" thread, lol. Is there a muffler that will eliminate the drone from my truck? I have significant drone between 1500-1800 RPMs. It comes on slowly about 1500 and drops off quickly about 1800. I have Doug Thorley LT headers, stock y-pipe with gutted cats, a 3"x24" bullet into a Flowmaster Delta 40 3" in and dual 2 1/2" tails going out the back under the bumper. How much does sound dampening matting on the rear cab wall help?