These BBK Performance shorty unequal Length exhaust Headers are designed as a direct fit for all 1986-1993 Ford Mustang 5.0 applications and will work with all factory and aftermarket H and X pipes. Every exhaust headers is constructed with 1-5/8" CNC mandrel bent tubing that offers unrestricted exhaust flow for increased horsepower and torque over factory OEM manifolds. As with all BBK Performance exhaust headers they feature a 3/8. All headers are robotically and precision hand welded and then pressure tested to ensure years of reliabilty and performance in the real world. All BBK exhaust header kits include new exhaust header gaskets, header bolts and hardware to complete the installation..