After restoring my 1970 Dodge Coronet RT Convertible a few years ago, I installed a complete 2 1/2 inch TTI H pipe exhaust system on my car. It came with DynoMax Turbo mufflers. They are oval, and the body of them is 20 inches long. The engine is a stock 440 4 bbl, auto trans. with stock exhaust manifolds on it. When cruising between 25 and 45 miles per hour the drone is deaffening!!!!! Once I hit 50 miles per hour and up, it fades into a nice tolerable rumble. But upon letting off the gas pedal and the speed hits 45 MPH and lower, the drone comes back. I called the tech. dept. at DynoMax and they told me it is a 3 chamber muffler and the quietest one they make. Anyone else out there in Mopar Land that has dealt successfully with this problem? Any other mufflers out there that would have a LIGHT RUMBLE WITHOUT the DRONE? Thanks for any and all replies!