Amazing kit! Did the switch off the H-pipe for a day in my 66ft fastback. Just lengthen or shorten the tubes and it adjusts the width of the tubes to your preference. So measure 3 times and probably at least halve. In terms of performance, I felt an increase in the midrange and gave the car a smoother tone when idling. The car is designed for sleeping. But the stroker I built for it should overclock and be happy above 5k (at least for Windsor). And I LOVE the sound it gave the system at higherβ¦