Exhaust: refining my H-pipe questions...
Reply #7 –
I've always had an H-Pipe (before the X-Pipe thing came around) since I was in high school in the mid-eighties.My '76 Grand Prix had one (not factory) with a 455 from a '71 GTO.I had read YEARS ago about their function and haved used them ever since.Mopars and Pontiac musclecars used them for good reason,to get every last horsepower they could.Everything I read said that the crossover adds a little power.Perhaps you won't feel it in the seat of your pants,but every little bit adds up.