Doug's Headers D303Y 1 3/4" Tri-Y Header Chevrolet Truck Big Block Chevrolet 68-87 Metallic Ceramic Coating
Part Number: D303YUPC: 694342506988
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Doug's Headers D303Y 1 3/4" Tri-Y Header Chevrolet Truck Big Block Chevrolet 68-87 Metallic Ceramic Coating
Qty: 1Disclaimer
Federal and state "anti-tampering" laws regulate modifications that affect emissions from motor vehicles and prohibit the sale, installation, and on-highway use of any add-on or modified emissions-related part on any pollution-controlled vehicle unless the part has received an exemption from the California Air Resources Board ("CARB") or is considered an exempt or replacement part. If a part has a California Executive Order Exemption (aka an EO #) or meets the requirements for an exempt part such as a Cat Back Exhaust system or is considered a replacement part, it is legal for sale or use in all 50 states. We are required by law to inform you about the legality of parts that we manufacture and sell and will refuse the sale of certain parts if the following requirements are not conformed with. Use of non compliant parts for purposes other than stated can result in a citation, fines, and/or confiscation of the vehicle. For the ordered parts listed below, you must certify, by clicking one of these boxes that you are using the product in the manner stated and for the application as specified by the manufacturer.
We cannot sell this part for use on a 1975 or Newer On Highway vehicle. It will not be added to your Cart.
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- Highlights
- Applications and Footnotes
- Additional Information
- Download Instruction Manual
Highlights
- 3/8" Thick machined flanges...no warping
- CNC mandrel bent tubes... accurate fit & better flow
- Tri-Y headers yield maximum power from off idle to 4500 RPM making them well suited for applications demanding maximum mid-range torque with maximum fuel economy
- Heavy 16 gauge tubing...longer life
- Tubes are pre-polished to remove scratches and the header is finished with a Metallic Ceramic Thermal Barrier Coating polished to a high luster appearance offering corrosion and heat resistance up to 1400 degrees
Applications and Footnotes
Chevrolet - Class A (chevrolet chassis) |
||||||||||||
| YEARS | 75 - 91 | |||||||||||
| ENGINES | 396-502 | |||||||||||
| EMISSION CODE | ||||||||||||
| A/C | Y | |||||||||||
| P/B | Y | |||||||||||
| P/S | Y | |||||||||||
| AUTO COL | Y | |||||||||||
| AUTO FLR | Y | |||||||||||
| STD COL | N | |||||||||||
| STD FLR | N | |||||||||||
| TUBE SIZE (in.) | 1 3/4 - 2 | |||||||||||
| COLLECTOR SIZE (in.) | 2 1/2 | |||||||||||
| PORT SHAPE | SAP | |||||||||||
| Available with optional smog pump provision. Dual smog pump applications add DP to the end of header part number. Single smog pump applications add SP to end of header part number | ||||||||||||
| Carbureted applications only | ||||||||||||
| Fits P30 chassis | ||||||||||||
| Non catalytic converter equipped. | ||||||||||||
| Tri-Y design | ||||||||||||
Chevrolet/GMC - GMC 2WD TRUCKS & SUV |
||||||||||||
| YEARS | 68 - 87 | |||||||||||
| ENGINES | 396-502 | |||||||||||
| EMISSION CODE | ||||||||||||
| A/C | Y | |||||||||||
| P/B | Y | |||||||||||
| P/S | Y | |||||||||||
| AUTO COL | Y | |||||||||||
| AUTO FLR | Y | |||||||||||
| STD COL | Y | |||||||||||
| STD FLR | Y | |||||||||||
| TUBE SIZE (in.) | 1 3/4 - 2 | |||||||||||
| COLLECTOR SIZE (in.) | 2 1/2 | |||||||||||
| PORT SHAPE | SAP | |||||||||||
| Available with optional smog pump provision. Dual smog pump applications add DP to the end of header part number. Single smog pump applications add SP to end of header part number | ||||||||||||
| Big block frame stands and motor mounts must be used to insure proper engine location and header fit. | ||||||||||||
| Does not fit 4 speed applications with bell housing mounts | ||||||||||||
| Non catalytic converter equipped. | ||||||||||||
| Tri-Y design | ||||||||||||
Chevrolet/GMC - 1/2, 3/4, 1 Ton / 1500, 2500, 3500 TRUCKS |
||||||||||||
| YEARS | 68 - 87 | |||||||||||
| ENGINES | 396-502 | |||||||||||
| EMISSION CODE | ||||||||||||
| A/C | Y | |||||||||||
| P/B | Y | |||||||||||
| P/S | Y | |||||||||||
| AUTO COL | Y | |||||||||||
| AUTO FLR | Y | |||||||||||
| STD COL | Y | |||||||||||
| STD FLR | Y | |||||||||||
| TUBE SIZE (in.) | 1 3/4 - 2 | |||||||||||
| COLLECTOR SIZE (in.) | 2 1/2 | |||||||||||
| PORT SHAPE | SAP | |||||||||||
| Available with optional smog pump provision. Dual smog pump applications add DP to the end of header part number. Single smog pump applications add SP to end of header part number | ||||||||||||
| Big block frame stands and motor mounts must be used to insure proper engine location and header fit. | ||||||||||||
| Does not fit 4 speed applications with bell housing mounts | ||||||||||||
| Non catalytic converter equipped. | ||||||||||||
| Tri-Y design | ||||||||||||
Chevrolet/GMC - 1 Ton / 3500 Crew, Standard Cab DUALLY |
||||||||||||
| YEARS | 73 - 91 | |||||||||||
| ENGINES | 396-502 | |||||||||||
| EMISSION CODE | ||||||||||||
| A/C | Y | |||||||||||
| P/B | Y | |||||||||||
| P/S | Y | |||||||||||
| AUTO COL | Y | |||||||||||
| AUTO FLR | Y | |||||||||||
| STD COL | Y | |||||||||||
| STD FLR | Y | |||||||||||
| TUBE SIZE (in.) | 1 3/4 - 2 | |||||||||||
| COLLECTOR SIZE (in.) | 2 1/2 | |||||||||||
| PORT SHAPE | SAP | |||||||||||
| Available with optional smog pump provision. Dual smog pump applications add DP to the end of header part number. Single smog pump applications add SP to end of header part number | ||||||||||||
| Big block frame stands and motor mounts must be used to insure proper engine location and header fit. | ||||||||||||
| Does not fit 4 speed applications with bell housing mounts | ||||||||||||
| Non catalytic converter equipped. | ||||||||||||
| Tri-Y design | ||||||||||||
Chevrolet/GMC - 1 Ton / 3500 Crew, Standard Cab DUALLY |
||||||||||||
| YEARS | 73 - 91 | |||||||||||
| ENGINES | 396-502 | |||||||||||
| EMISSION CODE | ||||||||||||
| A/C | Y | |||||||||||
| P/B | Y | |||||||||||
| P/S | Y | |||||||||||
| AUTO COL | Y | |||||||||||
| AUTO FLR | Y | |||||||||||
| STD COL | Y | |||||||||||
| STD FLR | Y | |||||||||||
| TUBE SIZE (in.) | 1 3/4 - 2 | |||||||||||
| COLLECTOR SIZE (in.) | 2 1/2 | |||||||||||
| PORT SHAPE | SAP | |||||||||||
| Available with optional smog pump provision. Dual smog pump applications add DP to the end of header part number. Single smog pump applications add SP to end of header part number | ||||||||||||
| Big block frame stands and motor mounts must be used to insure proper engine location and header fit. | ||||||||||||
| Does not fit 4 speed applications with bell housing mounts | ||||||||||||
| Non catalytic converter equipped. | ||||||||||||
| Tri-Y design | ||||||||||||
Chevrolet/GMC - Blazer / Jimmy, Suburban, Tahoe / Yukon |
||||||||||||
| YEARS | 68 - 87 | |||||||||||
| ENGINES | 396-502 | |||||||||||
| EMISSION CODE | ||||||||||||
| A/C | Y | |||||||||||
| P/B | Y | |||||||||||
| P/S | Y | |||||||||||
| AUTO COL | Y | |||||||||||
| AUTO FLR | Y | |||||||||||
| STD COL | Y | |||||||||||
| STD FLR | Y | |||||||||||
| TUBE SIZE (in.) | 1 3/4 - 2 | |||||||||||
| COLLECTOR SIZE (in.) | 2 1/2 | |||||||||||
| PORT SHAPE | SAP | |||||||||||
| Available with optional smog pump provision. Dual smog pump applications add DP to the end of header part number. Single smog pump applications add SP to end of header part number | ||||||||||||
| Does not fit 4 speed applications with bell housing mounts | ||||||||||||
| Non catalytic converter equipped. | ||||||||||||
| Tri-Y design | ||||||||||||
Additional Information
Doug's 2/4 WD TRUCK HEADERS Tri-Y Metallic Ceramic Coated 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 the vehicles they are intended to fit and are re-checked numerous times during the design and manufacturing process.
Download Instruction Manual
Emissions Code
PerTronix Performance Ignition and Exhaust Brands use a voluntary product identification program whereby all emission sensitive products can be identified by placing numbered labels in product packaging and listing corresponding numeric codes next to each part number. The corresponding numbers and explanations are as follows:
This product has been granted a California Air Resources Board (CARB) Executive Order (EO Number) Exemption. It is 50 State Legal when installed on the appropriate vehicle per the Manufacturer’s Application Guide and Installation Instructions.
This product is legal for use on 1975 and older Non-Catalyst equipped vehicles and is considered a “Replacement Part” per California Air Resources Board regulations, providing ALL emissions sensitive components are retained, including EGR, A.I.R., Heat Risers, etc. and any original or retrofit PCV or NOx device is required for the year of the vehicle. Failure to retain any of these components, or use on ANY originally catalyst equipped vehicles, would render this product illegal for street or off highway use and may only be used for Closed Course Competition.
This product is ILLEGAL for street or off highway use and is only intended for Closed Course Competition use and may never be operated on the street or for off highway use, except for 1965 and older US manufactured, California Certified vehicles; 1967 and older foreign manufactured vehicles, which may have this product installed as long as the vehicle still meets emissions standards for the year of the vehicle and retains any original or retrofit emissions control devices, including EGR, A.I.R. and any NOx device required for the year of the vehicle.
This product is considered a Replacement part per CARB and EPA regulations for emissions compliance and is legal for sale and use on all vehicles in all 50 states when installed according to the Manufacturer’s Application Guide and Installation Instructions.
This product is legal for street or off highway use in states that do not required California EO certification. PerTronix has reasonable basis (prior testing) and believe that this product allows the vehicle to operate within the legal emissions standards in the states that accept the legal provisions of the Clean Air Act and EPA Memorandum 1A. This product is not legal for street or off highway use in states that require CARB EO’s and may only be sold or used for Closed Course Competition use in those states.
This product is certified by the manufacturer as being a Non-Emissions sensitive part and therefore does not require emissions certification as emissions regulations are not applicable.
This product is designed for swapping a non-original engine into a vehicle that did not offer it. Laws vary by state regarding emissions regulations for engine swaps. This product is illegal for Street or Off Highway use on any 1975 or newer vehicle originally equipped with a catalytic converter and may further be illegal depending on state or federal engine swap emissions laws regardless of vehicle year and would therefore only be legal for Closed Course Competition use.
