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Doug Thorley Tri-Y Headers


Doug Thorley
Doug Thorley Tri-Y Headers

Product images may differ from actual product appearance.

The Tri-Y was invented by Doug Thorley Headers and is designed to match the synchronization of the engine's firing order, thus maximizing exhaust scavenging.

Doug Thorley Tri-Y Headers create optimum torque and the greatest horsepower gains in comparison to any other design. They yield maximum power from idle to 4500 RPM while adhering to strict emissions standards. Engineered to be well-suited for multiple applications, power significantly increases at mid-range RPM for exceptional efficiency at highway speeds. Fuel economy and low-end torque are improved; back pressure, engine heat, and weight are all reduced.

  • 14-gauge steel tubing and 3/8" flanges
  • Easy installation
  • 50-state legal


  • 2 Products
    General Motors

    702-THY-364Y-S-C
    Tri-Y Header
  • 1973-87 GM Truck
  • 1973-91 Suburban/Blazer/Jimmy 283-400 4WD
  • Ceramic Coated
  • 1-5/8" Primaries
  • 2-1/2" Collector
  • $666.00
    Order Today Ships 04/30/15
    Suzuki

    702-THY-716Y-SS
    Tri-Y Header
  • 1992-99 Samurai/Sidekick/Geo Tracker 1.3L-1.6L 16V
  • 304 Stainless Steel
  • 1-1/2" Primaries
  • 2-1/2" Collector
  • $326.00
    Order Today Ships 04/30/15

    2 Products