Hedman Hedders’ Street Legal Headers for C4 Corvettes

Hedman 84-91 C4 Corvette Emissions Legal Headers - 66447 - rgb

As a result of emissions regulations, the 350 small block V8, used in the C4, was severely limited in its ability to deliver power. Hedman’s Hedders is here to address the problem with its latest headers. Directly replacing the factory exhaust manifolds, these parts are engineered from the ground up to maximize exhaust flow while keeping the factory catalytic converter locations the same. Learn more about getting your C4 exhaling better to improve torque and horsepower with these latest headers from Hedman’s Hedders below.

Official Release:

The introduction of the C4 Corvette for the 1984 model year was the first complete redesign of the Corvette since the C2 debuted in 1963 and was packed with new technology like aluminum brake calipers and suspension arms as well as a one-piece targa top. Due to the increased emissions regulations of the time however, the 5.7L V8 Chevy small block was not as much of a powerhouse as it once was. Thankfully, Hedman Hedders now has a complete line of 50-state emissions legal headers designed to help the diminutive 350 reach its full potential, and restore some of that lost power.

Hedman’s full-length headers are engineered to maximize exhaust flow while maintaining the factory catalytic converter locations. 50-state legal under C.A.R.B. E.O.# D-167-33 and classified as a direct replacement for the factory exhaust manifolds, these headers are anything but stock. They allow your C4 Corvette to exhale better, significantly improving its torque and performance. Available in either Hedman’s Standard Duty design or Ultra-Duty ELITE Series with bullet-proof 3/8-inch flanges and thicker-walled 14-gauge primaries, all versions feature 1 5/8-inch mandrel-bent primaries and 3-inch ball & socket style collectors. Each set comes complete with weld-on header reducers that allow the integrated ball-and-socket collectors to easily bolt up to the factory exhaust and create a durable, gasket-free seal. Mounting hardware, instructions, and the mandatory E.O. sticker for your engine compartment are also included.

Standard-Duty C4 Corvette headers are available either in an uncoated finish (#68447 w/EGR; #68441 no/EGR) or with Hedman’s HTC polished ceramic-metallic coating for protection up to 1400 degrees Fahrenheit (#66447 w/EGR, #66441 no/EGR). The Ultra-Duty ELITE Series headers also come finished in Hedman’s HTC hi-temp coating (#68487 w/EGR, #61448 no/EGR).


  • Replace factory exhaust manifolds while keeping catalytic converter stationary
  • Better exhalation, better torque
  • Available in Hedman’s Standard Duty or Ultra-Duty ELITE Series

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About the author

David Chick

David Chick comes to us ready for adventure. With passions that span clean and fast Corvettes all the way to down and dirty off-road vehicles (just ask him about his dream Jurassic Park Explorer), David's eclectic tastes lend well to his multiple automotive writing passions.
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