Bassani Headers for Mustang 1999-04 Mach 1 4.6L 4V MANUAL.* Ceramic Coated * Mid-Length Headers for Manual Transmission only * 1 5/8, 14g individual primary tubes * 3/8 thick laser-cut flange, with a 4 into 1 collector, 2 1/2 diameter * 4V Oval ports * Bolts directly up to Bassani 5 pc. Power X. Adaptors included * Unsurpassed quality and fit, superior materials and expert craftsmanship * Utilizes mandrel bent 14 gauge carbon steel primary tubes for durability * Exclusive “Extractor Collector: induces a scavenging effect and further improves performance. * S.S. Comp TM Stainless Header Gaskets cure header leaks. * Ball and socket exit connectors for a gasket-free connection to your Y-pipe or X-pipe crossover section * Bassani Headers include all nuts, bolts, gaskets, hardware and detailed instructions for a perfect fit * Standard finish is industrial chrome, high temperature ceramic coating optional * 50 State Legal for most states (see notes on specific models) * Made in the U.S.A. Bassani’s headers feature mandrel bent 14 gauge mild steel primary tubes, Extractor Collector, gasket-less ball and socket connectors. Every header application comes complete with premium gaskets, nuts, bolts, hardware and detailed instructions.