For 2000-2006 BMW M54 Engine | E46 320i/325i/330i Z3 Z4 Exhaust Header Stainless Steel Sport Exhaust Headers for BMW 323i /328i , and manual or automatic transmissions. Models with air pumps may require modifications. These high performance headers were developed in Germany and are manufactured out of heavy gauge T304 stainless steel for long life. They are intended for track and off road use only unless you weld in catalytic converters. Kit comes complete with gaskets. Left Hand Drive models only. Not for xi four wheel drive models.Replacing or upgrading your exhaust header is necessary for both engine performance and sound. Whether on or off the track, exhaust headers provide more horsepower and improved exhaust sound. SPELAB offers many products to help you create your own custom engine headers. It's really easy and convenient to use: direct bolt-on, no modification needed.  Fitment: 2000-2006 BMW Models: 320i / 325i / 330i E46 (2.2L, 2.5L & 3.0L) 2000-2002 BMW Z3 Models: E36/E37, E36/E38 (2.2L, 2.5L & 3.0L) 2002-2005 BMW Z4 Models: E85, E86 (2.2L, 2.5L & 3.0L) Engine Fitment: Engine M54B22: 2000–2006 E46 320i, 330Ci 2000–2002 E36/7 Z3 2.2i 2002–2005 E85 Z4 2.2i Engine M54B25: 2000–2002 E36/7 Z3 2.5i 2000–2006 E46 320i, 325xi, 330Ci 2000–2004 E46 325ti 2002–2005 E85 Z4 2.5i Engine M54B30: 2000–2006 E46 320i, 330xi, 330Ci 2000–2002 E36/7 Z3 3.0i 2002–2005 E85 Z4 3.0i If your BMW's engine is M52. Click there Header for M52 Specifications: Brand Name: SPELABSKU: ES08335Certificate: ISO9001:2000Application: Automobile Exhaust HeaderMaterial: 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. Replacing or upgrading your exhaust header is necessary for both engine performance and sound. Whether on or off the track, exhaust headers provide more horsepower and improved exhaust sound. SPELAB offers many products to help you create your own custom engine headers. It's really easy and convenient to use: direct bolt-on, no modification needed.