bird 400. more for sound quality? I just bought a 1968 Pontiac firebird 400. The car still has the orignial exhaust manifold. I am wanting to make the car sound good and wondering what kind of headers I should go with I am also going with a mild cam. I don't want the car to have an outrageous noise but something very noticeable. Also wondering whats a good muffler to use. I am going to be using the turn down exhaust. another question is to use x pipe or what. I am new to this car stuff and I am looking for the muscle car sound. any info will be appreciated! thanks