I installed a walker BTM on my stock exhaust a couple of years ago. No matter what the speed, I have a "drone" or "resonance" at about 1650 to 1950 RPM. The sound really annoys me on the highway. I have searched and found suggestions of reversing the muffler, and shortening / lengthening the distance of the muffler in the exhaust system. I have a service body on my truck. Has anybody cut the exhaust before it wraps over the rear end? I am ready to try it.