Exhaust Manifold for 1983-1993 Ford Mustang SVO Thunderbird XR4Ti 2.3L SPELAB Replacing or upgrading your exhaust manifold is necessary for both engine performance and sound. Whether on or off the track, the exhaust manifold provides more horsepower and improved exhaust sound. Fitment: 1979-1993 Ford Mustang 2.3L Turbocharged1983-1989 Ford Thunderbird Turbo Coupe 2.3L Specifications: Brand Name: SPELABModel: EM29102XCertificate: ISO9001:2000Application: Automobile Exhaust ManifoldMaterial: Stainless SteelSurface: Mirror Polish Exhaust Header VS Manifold, which is the better choice? The structural differences between exhaust headers and manifolds are the material and size. From the material, exhaust headers are made of lighter, thinner steel, while exhaust manifolds are made of thick iron. Exhaust headers are also longer than exhaust manifolds. When in use, exhaust manifolds create back pressure, which lowers performance. Because each cylinder of the engine is given its own tube, however, headers eliminate this problem; thus, allowing the gases to exit without the creation of back pressure. Therefore, exhaust headers are a BETTER choice than an exhaust manifold.