Measuring to Ensure Fit

Why is there is such a price difference between header brands?

Header development and design is complex and requires a substantial amount of time and resources to do the job right! Many manufacturers are unwilling to make the commitment and instead offer compromised headers at lower prices.

Doug's will not compromise performance, quality or fit to compete with inferior designs at cheap prices. Every Doug's header is tuned with the proper tube size and length to efficiently remove all the exhaust from each cylinder, reducing pumping losses resulting in a dramatic increases in horsepower and torque. Doug's headers are carefully developed on vehicles they are intended to fit and are re-checked numerous times during the design and manufacturing process.

What is included with a set of Doug's Headers

What is included with a set of Doug's headers?

Every Doug's header comes with all the necessary mounting hardware, collector reducers or connector pipes, premium gaskets and detailed installation instruction sheets. Our extra thick gaskets are rated up to 1100°F, pressures to 3700 psig (255 bar), and are designed for an exact port match with Doug's headers. We do not recommend the use of other after-market gaskets. Doug's premium gaskets are sold separately HERE!

Display of different coatings

What finish is applied to Doug's headers?

Most Doug's headers are available in raw steel for individual customizing. However, the preferred finish continue to be our Metallic Ceramic Thermal Barrier Coating (MCTBC). MCTBC protects and extends the life of headers by creating a thermal barrier that significantly lowers under hood temperatures and protects the substrate metal from thermal fatigue. After MCTBC is applied, it is polished with a vibratory finishing process that produces a high luster aluminum appearance. The polishing process compresses and activates the coating, which increases the surface hardness to produce a finish that is 60% more corrosion resistant than an unpolished surface. This coating is easy to maintain and will last for years under normal operation conditions.

NEW for 2014 is our Hi-Temp Black Coating available on Doug's Headers and side tubes. An affordable priced alternative to our MCTBC, our Hi-Temp Black finish provides good corrosion and heat protection when compared to many of the "cheaper" header finishes being applied by our competitors.

Do all Doug's headers have the same basic design?

No, absolutely not. Doug's headers are designed for specific applications. The type of header design will change depending on the intended vehicle usage and emissions requirements. Doug's Headers utilize 4 types of designs for conventional V-8 applications: Long-Tube, Tri-Y, Manifold Replacement, and Mid-Length. Below is further detail on our header designs with Tight Tuck/Block Hugger included for reference:

Long Tube or Full Length

Long tube headers will give the greatest increases in horsepower and torque across the entire RPM spectrum. The choice of racers worldwide, a set of Doug's Long Tube headers are meticulously designed for the discriminating car owner who wants maximum power and the highest quality header on the market.


Doug's Headers is the originator of the popular Tri-Y design for cars and trucks. The unique, shorter, paired primary tubes increase mid rang torque without sacrificing top end power. Tri-Y's are a great choice for daily driven vehicles and heavy trucks looking to increase power from idle to 4500 RPM and maintain maximum fuel efficiency.

Manifold Replacement

Manifold replacement headers are designed to replace the original manifolds and retain all the original equipment emissions and exhaust connections while offering a performance boost. In many instances these headers have been issued a California Air Resources Board EO Exemption making them Emissions Legal in all 50 states. Read more on CARB EO Exemptions here

Mid Length

Mid-Length headers, sometimes referred to as Clippsters, offer better performance gains than Manifold Replacement or Block Hugger type headers while keeping ground clearance at a maximum. Perfect for today's lowered stance cars and trucks where long tube headers might hang too low.

Tight Tuck or Block Hugger

4-tube tight tuck headers are the best solution for narrow frame rail street rods.

How important is flange and tubing thickness to header performance?

A properly machined and finished header flange eliminates annoying exhaust leaks which lead to horsepower loss. Doug's Headers utilize 3/8" flanges. Thicker flanges hold up to heat better and are less likely to warp. Late model vehicles and high performance muscle cars product super heated conditions that can warp thinner flanges.

Header tubing thickness and proper fixture welding techniques can affect the longevity of a header. Doug's Headers utilizes 16 gauge tubing and are built in heavy duty jig fixtures which eliminate heat distortion and movement of the individual header tubes. Each header is welded using cyclical welding techniques which reduce tube distortion.

What kind of performance gainst can I expect by installing a set of headers?

The addition of a set of headers typically adds 15-20% more horsepower and torque. How much performance is gained depends on the condition of your vehicle and any additional upgrades you have made to the engine (intake, fuel delivery, cam, and ignition). All of our headers are designed and tested with appropriately sized tube diameters and lengths to bring you maximum performance and engine efficiency.

What modifications are encessary to make my headers fit?

Our product development department takes a substantial amount of time and effort to design our headers, so you don't have to! With 40 years of expertise in designing, manufacturing and installing exhaust products we can offer a quality product that fits. Most of our street rod and muscle car header applications are direct bolt on applications with little welding required. If you do not feel comfortable with welding operations find a professional exhaust shop to help with the installation.

Technician Working

What should I do if I encounter an installation problem with my header?

Header installation for the most part can be accomplished with simple hand tools, a floor jack and jack stands. Some applications can be very time consuming due to limited space in the engine compartment. Should you encounter a fitment problem do not attempt to modify or alter the header in any way or your warranty will become void. Call our knowledgeable technical staff for assistance at (909) 547-9058. Headers returned without prior written authorization will be refused. Read our complete warranty policy here.