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Doug's Headers 66003 Seal-4-Good Collector Gaskets 3.5 Inch

Manufacturer

Doug's Headers

<h3>A Legend Born in the Golden Age of Muscle Cars</h3><p><a href="/191-dougs-headers">Doug's Headers</a> traces its roots back to 1958, when the original shop opened its doors as a small muffler operation in Whittier, California. Within a few short years, the company had grown into one of the most recognized names in performance exhaust — and the iconic <strong>&quot;Headers by Doug&quot;</strong> decal became a badge of honor on some of the fastest drag cars in the country. The brand's founder was eventually inducted into five separate drag racing halls of fame, a testament to the impact his engineering philosophy had on the sport.</p><p>In January 2005, Doug's Headers joined the PerTronix family of performance brands, gaining expanded manufacturing resources while staying true to the founding principle: <em>the customer should only have to install the headers, not re-engineer them to fit their vehicle.</em> Today, product development and distribution are headquartered out of a modern 40,000-square-foot facility in Irwindale, California, where every design is rigorously developed and quality-checked before it reaches the enthusiast.</p><h3>Engineering That Delivers Real-World Results</h3><p>At the heart of every Doug's product is a commitment to proper tube sizing and collector geometry. Each <a href="/191-dougs-headers-exhaust-header-5848">exhaust header</a> is engineered with precisely calculated primary tube diameter and length to efficiently scavenge exhaust gases from every cylinder — reducing pumping losses and unlocking measurable gains in horsepower and torque across the RPM range. Whether you're building a street cruiser or a dedicated track car, there's a Doug's header designed specifically for your application.</p><p>Doug's offers three primary header configurations to match different performance goals:</p><ul><li><strong>Long Tube Headers</strong> — Maximize horsepower and torque across the entire RPM spectrum, making them the go-to choice for racers and high-performance builds.</li><li><strong>Mid-Length Headers</strong> — Strike a balance between performance and practicality, particularly for lowered vehicles where ground clearance is a concern.</li><li><strong>TRI-Y Headers</strong> — Doug's is the originator of the TRI-Y design for cars and trucks. The paired primary tube layout emphasizes mid-range torque, making these headers an excellent choice for daily drivers, heavy-duty trucks, and towing applications.</li></ul><p>The lineup extends beyond headers to cover the full exhaust system. Doug's <a href="/191-dougs-headers-exhaust-muffler-5872">exhaust mufflers</a> — including the signature sidetube glasspack-style units for classic Corvette sidemount systems — are engineered to complement their headers and let owners fine-tune exhaust note and volume. Proper sealing is equally important, and Doug's <a href="/191-dougs-headers-exhaust-manifold-flange-gasket-5832">exhaust manifold flange gaskets</a> are purpose-built to deliver leak-free performance with every installation. Rounding out the system, quality <a href="/191-dougs-headers-exhaust-clamp-5816">exhaust clamps</a> ensure that every joint stays sealed mile after mile.</p><h3>Built for Muscle Cars, Street Rods, Trucks &amp; More</h3><p>Doug's Headers products are engineered for a broad range of vehicles — from classic muscle cars and street rods to trucks, SUVs, and motorhomes. The catalog includes dedicated fitments for popular engine swap applications, with specific designs for modern powerplants dropped into vintage chassis. Every kit ships with all necessary mounting hardware, so installation is straightforward from day one.</p><p>With over six decades of exhaust engineering expertise and the backing of the PerTronix performance family, Doug's Headers continues to be the standard by which performance exhaust headers are measured.</p>

Part Number

66003
07/21/2036 10:59 PM
Sale Price

$27.41

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Product Details

Doug's Headers 66003 Seal-4-Good collector gaskets are designed to provide a superior seal between your exhaust headers and collector pipes. These high-quality gaskets feature a 3.5-inch diameter opening, making them compatible with a wide range of performance exhaust systems.

Key Features:

  • 3.5-inch diameter collector gasket size
  • Seal-4-Good construction for reliable, leak-free performance
  • High-temperature resistant materials withstand extreme exhaust heat
  • Prevents exhaust leaks at the critical header-to-collector junction
  • Designed to work with Doug's Headers and most aftermarket performance headers

These collector gaskets are essential components for maintaining proper exhaust system sealing and preventing power-robbing leaks. The Seal-4-Good design ensures a durable seal that holds up under the demanding conditions of high-performance engines.

Good service

EASY TO NAVIGATE, FOUND EXACTLY WHAT I NEEDED!!

Very quick and easy

Great service

Great service

Haven't installed yet but delivery time excellent.

Fast shipping and great price. A+++

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