Pypes Exhaust XFM10 1979-1995 Mustang 5.0 2.5" Off Road X-Pipe Fits 1979-1995 Mustang 5.0L with stock or short headers 1979-1986's need a pre-existing dual exhaust (Single exhaust was stock) Features two threaded holes for O2 sensors X-pipes balance out the exhaust pressure; Allows for more power and torque compared to H-pipes Pypes Performance Exhaust part # XFM10