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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


  • 18 Products
    Ford

    702-214Y-FI3-C
    Tri-Y Header
  • 1993.5-1995 Ford 460 Class C Motorhome
  • Ceramic Coated
  • 1-3/4" Primaries
  • 2-1/2" Collector
  • $789.99
    Order Today Ships 09/05/14
    General Motors

    702-300Y-C
    Tri-Y Header
  • 1961-66 GM Pickup/Truck 283-400
  • 1973-87 GM Pickup/Truck 283-400
  • Ceramic Coated
  • 1-5/8" Primaries
  • 2-1/2" Collector
  • $648.99
    Order Today Ships 09/05/14
      702-300Y-DA
    Tri-Y Header
  • 1961-66 GM Pickup/Truck 283-400
  • 1973-87 GM Pickup/Truck 283-400
  • With Dual Air Injection
  • Chrome Finish
  • 1-5/8" Primaries
  • 2-1/2" Collector
  • $656.99
    Order Today Ships 09/05/14
      702-300Y-DA-C
    Tri-Y Header
  • 1961-66 GM Pickup/Truck 283-400
  • 1973-87 GM Pickup/Truck 283-400
  • With Dual Air Injection
  • Ceramic Coated
  • 1-5/8" Primaries
  • 2-1/2" Collector
  • $656.99
    Order Today Ships 09/05/14
      702-300Y-S
    Tri-Y Header
  • 1961-66 GM Pickup/Truck 283-400
  • 1973-87 GM Pickup/Truck 283-400
  • With Single Air Injection
  • Chrome Finish
  • 1-5/8" Primaries
  • 2-1/2" Collector
  • $670.99
    Order Today Ships 09/05/14
      702-300Y-S-C
    Tri-Y Header
  • 1961-66 GM Pickup/Truck 283-400
  • 1973-87 GM Pickup/Truck 283-400
  • With Single Air Injection
  • Ceramic Coated
  • 1-5/8" Primaries
  • 2-1/2" Collector
  • $670.99
    Order Today Ships 09/05/14

    702-303Y-DA-C
    Tri-Y Header
  • 1975-00 Class A Motorhome P-30 Chassis Only
  • 1973-1987 Truck/Suburban/Blazer/Jimmy 366-454 2WD
  • With Dual Air Injection
  • Ceramic Coated
  • 1-3/4" Primaries
  • 2-1/2" Collector
  • $674.99
    Ships

    702-306Y2-C
    Tri-Y Header
  • 1990-00 GM Class A Motorhome 366-454, 4L80E
  • Ceramic Coated
  • 1-3/4" Primaries
  • 2-1/2" Collector
  • $807.99
    Ships

    702-310Y-1-C
    Tri-Y Header
  • 1999-12 Truck/Suburban/Tahoe/Yukon/Escalade/Denali
  • 4.8L-6.2L, 2/4WD, Off-Road Only (No Smog Fittings)
  • Ceramic Coated
  • 1-5/8" Primaries
  • 3" Collector
  • $651.99
    Order Today Ships 09/05/14

    702-333Y-C
    Tri-Y Header
  • 2008 G8 GT 6.0L LS2
  • Ceramic Coated
  • 1-3/4" Primaries
  • 2-1/4" Collectors
  • $683.00
    Order Today Ships 09/05/14

    702-337Y-C
    Tri-Y Header
  • 2010-11 Camaro SS 6.2L LS3/L99
  • Ceramic Coated
  • 1-3/4" Primaries
  • 2-1/4" Collectors
  • $726.00
    Order Today Ships 09/05/14

    702-375Y-C
    Tri-Y Header
  • 1967-78 Camaro 265-400
  • 1968-77 Nova 265-400
  • 1968-78 Chevelle/El Camino 265-400
  • Ceramic Coated
  • 1-5/8" Primaries
  • 2-1/2" Collectors
  • $634.00
    Order Today Ships 09/05/14
    Jeep/American Motors
      702-630Y-C
    Tri-Y Header
  • 1993-99 Grand Cherokee 318/360
  • Ceramic Coated
  • 1-5/8" Primaries
  • 2-1/2" Collector
  • $801.99
    Order Today Ships 09/05/14
    Suzuki
      702-700Y-C
    Tri-Y Header
  • 1983-95 Samurai/Sidekick/Geo Tracker 4WD 1.3L-1.6L 8V
  • Ceramic Coated
  • 1-1/2" Primaries
  • 2-1/2" Collector
  • $378.99
    Order Today Ships 09/05/14

    702-THY-716Y-C
    Tri-Y Header
  • 1992-99 Samurai/Sidekick/Geo Tracker 4WD 1.3L-1.6L 16V
  • Ceramic Coated
  • 1-1/2" Primaries
  • 2-1/2" Collector
  • $328.99
    Order Today Ships 09/05/14
    Toyota
      702-542Y-SO-C
    Tri-Y Header
  • 1981-84 Toyota Pickup 2/4WD 20R/22R
  • 1984.5-87 4Runner 2/4WD 20R/22R
  • SMOG Fittings & O2 Bung
  • Ceramic Coated
  • 1-1/2" Primaries
  • 2-1/4" Collector
  • $470.99
    Order Today Ships 09/05/14

    702-555Y-C
    Tri-Y Header
  • 1988-95 Toyota Pickup 2/4WD 20R/22R
  • Ceramic Coated
  • 1-1/2" Primaries
  • 2-1/4" Collector
  • $427.00
    Order Today Ships 09/05/14

    702-560Y-C
    Shorty Tri-Y Header
  • 2007-08 Tundra 2/4WD 5.7L
  • Ceramic Coated
  • 1-5/8" Primaries
  • 2-1/2" Collector
  • $760.00
    Order Today Ships 09/05/14

    18 Products