• Doug Thorley Headers THY-310Y-1-C

    Doug Thorley Headers Doug Thorley Hummer H2 4.8L-6.2L Race Use Only Tri-Y Headers - THY-310Y-1-C

    Doug Thorley Headers THY-310Y-1-C | Doug Thorley Hummer H2 4.8L-6.2L ("Race" Use Only) Tri-Y Headers; 1999-2012
    Doug Thorley Headers THY-310Y-1-C | Doug Thorley Hummer H2 4.8L-6.2L ("Race" Use Only) Tri-Y Headers; 1999-2012 Alternate Image 1
    Doug Thorley Headers THY-310Y-1-C | Doug Thorley Hummer H2 4.8L-6.2L ("Race" Use Only) Tri-Y Headers; 1999-2012 Alternate Image 2

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Product Description

SKU: THY-310Y-1-C

Doug Thorley Headers THY-310Y-1-C - Doug Thorley Hummer H2 4.8L-6.2L "Race" Use Only Tri-Y Headers; 1999-2012.

Doug Thorley Headers Warranty Policy


Unless otherwise specified, Doug Thorley Headers header products are warranted against defective materials and workmanship for as long as the original consumer purchaser owns said header product. Doug Thorley Headers exhaust products, defined as any component “downstream” of a Doug Thorley Headers header product or OE factory exhaust manifolds, are warranted against defective materials and workmanship for a period of 5 years from the original consumer purchase date. These limited warranties are offered solely to the original purchaser, are non-transferrable and proof of purchase is required for any warranty claims.

These warranties shall be limited to the repair, adjustment, and/or replacement of defective parts at the discretion of Doug Thorley Headers. Authorized product(s) returned will be repaired or replaced also at the discretion of Doug Thorley Headers, All warranties become void if any product shows evidence of any modification done without the express consent of Doug Thorley Headers, and includes mishandling, bending, welding, mutilation of parts, and insulating wrap products. Doug Thorley Headers is not responsible for any other expenses involved in a warranty claim, including any labor costs incurred by the customer in relation to defective parts, or shipping cost to or from Doug Thorley Headers. Nor shall Doug Thorley Headers be responsible for any damages, whether consequential, special, contingent or otherwise; or expenses or injury that may arise from the use of Doug Thorley Headers products.

The bluing and discoloration of chrome exhaust products is considered normal, as is the dulling of ceramic coated products, and as such, coatings are not covered under the terms of the warranty. Environmental exposure and rust apparent during the extended life of products is also considered normal and excluded from the warranty. Any Doug Thorley Headers product that has been discontinued from new sales for a period of 5 years or longer will no longer be eligible for replacement under terms of the warranty, the repair of any defective parts will be the only option. Any non-defective not-installed product may be returned for any reason within 30 calendar days of receipt, and will be subject up to a 20% restocking/repackaging fee.

About Doug Thorley Headers

History and information about Doug Thorley Headers and their products.

DOUG THORLEY HEADERS, an "all American made" company, has been in business for 50 years producing some of the world's best headers. DOUG THORLEY HEADERS is world famous for the invention of the tri-y header and for ease of installation. DOUG THORLEY HEADERS also introduced a new line of HDX–series of headers for sale that are super heavy duty and specifically designed for those who have motor homes, trucks and off-road vehicles that are susceptible to extreme conditions. DOUG THORLEY HEADERS also produces the finest SANRAIL header-exhaust available anywhere.

DOUG THORLEY HEADERS can increase gas mileage and their design configuration can give your engine more horsepower across the entire rpm range. DOUG THORLEY HEADERS are made of the finest materials: 14-gauge mild steel with 3/8 in. thick flanges and 5/16 in. collector rings and with a nickel chrome plated finish for a great look. All our coated products are coated inside and out. 3 layers inside, 5 layers and polish outside. DOUG THORLEY HEADERS have an O-ring welded into the flange and a high-temperature gasket to prevent leaks.

Their illustrious history in the field of designing and developing performance headers for the automotive industry is a testament to the fact that the DOUG THORLEY line of headers is nonpareil. The ever growing internationally competitive market demands that a company stay ahead of the game in both innovation and quality of product and DOUG THORLEY has managed to do just that because they know how important this investment is to you and they want to give you the best. The importance of the role in the functioning of your car’s engine is always taken into consideration when they design and manufacture their headers and their aim is to help increase the speed at which exhaust gases leave your engine. The DOUG THORLEY long tube headers for your Frontier, 4-Runner, Tacoma, Pathfinder, XTERRA, Firebird, Grand Prix, GTO, Lemans, Land Cruiser, Camaro, CHEVELLE, Nova and El Camino and available on the LMPERFORMANCE web site should afford you an increase in horsepower at uninterrupted high revolutions and they are the quintessential header for racing applications. And if you would rather go the route of the DOUG THORLEY SHORTIE headers then LMPERFORMANCE can help you there too and since the DOUG THORLEY SHORTIE headers take up less room in the engine compartment and are the better choice for lowered vehicles they may be just right for you, especially since they generally work with your existing exhaust components and still provide significant gains in power. LMPERFORMANCE also carries the inimitable tri-y header, one of DOUG THORLEY’s most efficient headers for sale, yet one that still improves horsepower significantly and the incredible WORX series headers for your Ford Mustang with its emphasis on racing and with maximum power gain of more than 25 horsepower and greater efficiency. In your search for the ideal header you won’t go wrong with DOUG THORLEY and LMPERFORAMANCE for exceptional quality.

LMPerformance.com carries DOUG THORLEY HEADERS, DOUG THORLEY SHORT HEADERS, DOUG THORLEY EXHAUST SYSTEMS, and DOUG THORLEY Y-PIPES for your Buick, Chevy, Ford, GMC, Hummer,Infinity, Jeep, Kia, Lexus, Nissan, Pontiac, Suzuki and Toyota at a very competitive price and, of course with the customer service you deserve.


California Residents: CARB WARNING: LMPerformance will not ship any products (ie. Headers, Off-Road pipes, non-Carb Approved Intakes, etc...) that are not CARB approved to California. This only affects CARB related products such that affect car performance and emissions where CARB approval is required.

California Residents: Prop 65 WARNING: This product MAY contain chemicals known to the State of California to cause cancer and birth defects or other reproductive harm. Wash hands after handling. For more information, visit www.P65Warnings.ca.gov

*** EMISSIONS EPA NOTE: Not legal for use on pollution-controlled motor vehicles. For off-road use only.The use of long tube headers with aftermarket cats, powerflo-x, h-pipe, x-pipe, crossover pipes with or without aftermarket cats or aftermarket cats are illegal for installation and use on emission-legal vehicles when operated on public streets or highways. They can only be legally used while participating in sanctioned motorsports racing events.

Purchasing one of these items, you agree that the long tube headers with aftermarket cats, powerflo-x, hpipe, xpipe crossover pipes with or without aftermarket cats or aftermarket cats purchased from Late Model Performance are solely being used for sanctioned motorsports racing events, and when installing or re-selling headers with aftermarket cats, powerflo-x crossover pipes with aftermarket cats or aftermarket cats, the end consumer is being made aware of and agrees to these terms of use.

California Residents: TIRE WARNING: LMPerformance will not ship Tires to California.

Legal: Some or all of these parts may not comply with Federal, State, Province, and/or Local laws, ordinances, and regulations. Buyer takes all responsibility to ensure that any modifications or upgrades that have done conform to all applicable laws and regulations for road use, especially pertaining to safety and emissions. LMPerformance is not responsible for buyer not complying with Federal, State, Province, and/or Local laws, ordinances, and regulations. This policy shall be in force for all past, current, and future purchases from LMPerformance, Inc. LMPerformance will not ship ANY non-CARB compliant products to California where California requires products to be CARB certified such as Catalytic Converters and Induction Kits.

FREE SHIPPING: Please note FREE Shipping refers to shipping within the contiguous continental US only. All other locations extra. Some items that require Truck Freight Delivery will require a Truck Freight surcharge. This surcharge is still a discounted shipping amount that is lower then the actual truck freight shipping charge that is charged to LMP. LMP will try to still give the lowest price possible for truck freight items.

IMAGES: Images may be a representation and may not reflect the actual product. Examples would be SPEC stage 3 clutch kits which all use the same photo.

TYPOS: LMPerformance tries to present the best most accurate information on our website. Sometimes we get mistakes in product information sent from vendors such as typos. We can not be responsible for these typos, if you see something that does not look right please let us know before ordering so we can double check for you first. LMPerformance will not pay for typos in any way, monetarily or otherwise.

Doug Thorley Headers THY-310Y-1-C Headers & Manifold Review(s)

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Search Terms: THY310Y1C THY-310Y-1-C DTH-THY-310Y-1-C DTHTHY310Y1C Doug Thorley Headers Doug Thorley Hummer H2 4.8L-6.2L ("Race" Use Only) Tri-Y Headers 4.8L6.2L TriY Exhaust, Mufflers & Tips Headers & Manifolds Doug Thorley Hummer H2 48L-62L ("Race" Use Only) Tri-Y Headers 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 THY-310Y-1-C