street force headers competition headers truck force headers footnotes 1 this system uses 21/4 o.d tubing we recommend using either the super competition aero chamber maximum flow or turbo mufflers in a 21/4 offset inlet/center outlet configuration see page 62 for complete muffler information 2 available with fittings to accommodate air injection manifold add a 0 in front of the part number when ordering 3 factory 4 wheel drive 4 exhaust systems can also be fabricated using either hooker super competition aero chamber mufflers maximum flow mufflers super competition turbo mufflers competition ...