You asked for the BTDT people? This is the deal. In the video above, the engine is plus 600hp. What the muffler test shows is the limitations of the muffler tested. The limitation of max HP. While it is strictly limited to that engine, installing the muffler that made, let’s just say 550hp, would show little improvement on a higher horsepower engine. So it is mostly valid. Anyone of those mufflers making over 500hp would suite your engine no matter the pipe size. What it comes down to is mostly personal factors of outside sound, inside sound & fitting the system in. All the mufflers used are short case mufflers. Longer case mufflers will be quieter. For my personal “Road bound DRIVER” vehicle I used the long case Dynomax Super Turbo muffler with tail pipes @ 2-1/2 inches. Also the power difference between the X & H pipe YOU will not ever feel on the top end. If your worried about ever last HP, then a short case muffler like the Hooker Max Flow or the similar Dyno Max@ 3 inches is what you want. Not overly concerned about max power but want to talk and listen to the radio, then the long case Dyno Max Super Turbo is your muffler. It is capable of the power you make. Been there done that!