Weld up your own headers. Dynatech kits are complete weld-up drag race header packages great for most popular NHRA, IHRA and E.T. Series race cars with Chevy power. Engineered for maximum flow, these kits feature equilized port exit angle, large radius mandrel bends and true equal length primary tubes. All headers and kits are designed to use slip-on header collectors. Each kit includes: 8 mild steel primary tubes, 2 CNC laser machined header flanges, 8 port gussets, 2 header gaskets, header bolts and U-tab kits for collector mounting. Collectors come in some kits as indicated.