Doug's Headers - D665

Doug's Headers D665 1 5/8" 4-Tube Shorty Header Ford Mustang Small Block Ford 64-73 Metallic Ceramic Coating

Doug's Headers D665 1 5/8" 4-Tube Shorty Header Ford Mustang Small Block Ford 64-73 Metallic Ceramic Coating

Part Number: D665 / UPC 694342519162
  • Doug's Headers D665 1 5/8" 4-Tube Shorty Header Ford Mustang Small Block Ford 64-73 Metallic Ceramic Coating

Product Info
  • 3/8" Thick machined flanges... no warping
  • CNC mandrel bent tubes... accurate fit & better flow
  • Mid length headers provide improved groungd clearance for popular muscle cars and street rods
  • 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

Ford - Mustang

    EMISSION       AUTO STD TUBE COLLECTOR PORT
YEARS ENGINES CODE A/C P/B P/S COL FLR COL FLR SIZE (in.) SIZE (in.) SHAPE
64 - 73 260-302 Y Y Y Y Y N Y 1 5/8 3 SAP
Header installation requires the use of the 1965-66 Non Hi-Po V8 clutch equalizer bar
Lakewood bell housings require clearancing for header tubes
Mid length design for maximum ground clearance
Must use 66 1/2 or later frame brackets (approx. 1" higher than 65 and early 66 style)
Use recommended C5ZZ16A052E "export brace" if shock mount center to center dimension is less than 33 3/4"
Will not fit GT40 "P" head

Mercury - Cougar

    EMISSION       AUTO STD TUBE COLLECTOR PORT
YEARS ENGINES CODE A/C P/B P/S COL FLR COL FLR SIZE (in.) SIZE (in.) SHAPE
67 - 73 260-302 Y Y Y Y Y N Y 1 5/8 3 SAP
Header installation requires the use of the 1965-66 Non Hi-Po V8 clutch equalizer bar
Lakewood bell housings require clearancing for header tubes
Mid length design for maximum ground clearance
Must use 66 1/2 or later frame brackets (approx. 1" higher than 65 and early 66 style)
Use recommended C5ZZ16A052E "export brace" if shock mount center to center dimension is less than 33 3/4"
Will not fit GT40 "P" head

 

 

Applications and Footnotes

Ford - Mustang

YEARS 64 - 73
ENGINES 260-302
EMISSION CODE
A/C Y
P/B Y
P/S Y
AUTO COL Y
AUTO FLR Y
STD COL N
STD FLR Y
TUBE SIZE (in.) 1 5/8
COLLECTOR SIZE (in.) 3
PORT SHAPE SAP
Header installation requires the use of the 1965-66 Non Hi-Po V8 clutch equalizer bar
Lakewood bell housings require clearancing for header tubes
Mid length design for maximum ground clearance
Must use 66 1/2 or later frame brackets (approx. 1" higher than 65 and early 66 style)
Use recommended C5ZZ16A052E "export brace" if shock mount center to center dimension is less than 33 3/4"
Will not fit GT40 "P" head

Mercury - Cougar

YEARS 67 - 73
ENGINES 260-302
EMISSION CODE
A/C Y
P/B Y
P/S Y
AUTO COL Y
AUTO FLR Y
STD COL N
STD FLR Y
TUBE SIZE (in.) 1 5/8
COLLECTOR SIZE (in.) 3
PORT SHAPE SAP
Header installation requires the use of the 1965-66 Non Hi-Po V8 clutch equalizer bar
Lakewood bell housings require clearancing for header tubes
Mid length design for maximum ground clearance
Must use 66 1/2 or later frame brackets (approx. 1" higher than 65 and early 66 style)
Use recommended C5ZZ16A052E "export brace" if shock mount center to center dimension is less than 33 3/4"
Will not fit GT40 "P" head

 

 

Key for abbreviations and acronyms
2V Two valve cylinder head
DP Dual Smog Pump (emissions device)
PSIG Pounds Per Square Inch Gauge
3V Three valve cylinder head
E.O. Executive Order
RD Round Port
4V Four valve cylinder head
EGR Exhaust Gas Recirculation (emissions device)
REC Rectangle Port
A/C Air Conditioning
FLR Floor
SAP Same As (cylinder head) Port
AUTO Automatice Transmission
MCTBC Metallic Ceramic Thermal Barrier Coating
SP Single Smog Pump (emissions device)
COL Column shift
OVL Oval Port
STD Standard Transmission
COLL Collector
P/B Power Brakes
T.P.I. Tuned Port Injection
DIA Diameter
P/S Power Steering

 

 

Highlights
  • 3/8" Thick machined flanges... no warping
  • CNC mandrel bent tubes... accurate fit & better flow
  • Mid length headers provide improved groungd clearance for popular muscle cars and street rods
  • 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

Ford - Mustang

EMISSION AUTO STD TUBE COLLECTOR PORT
YEARS ENGINES CODE A/C P/B P/S COL FLR COL FLR SIZE (in.) SIZE (in.) SHAPE
64 - 73 260-302 Y Y Y Y Y N Y 1 5/8 3 SAP
Header installation requires the use of the 1965-66 Non Hi-Po V8 clutch equalizer bar
Lakewood bell housings require clearancing for header tubes
Mid length design for maximum ground clearance
Must use 66 1/2 or later frame brackets (approx. 1" higher than 65 and early 66 style)
Use recommended C5ZZ16A052E "export brace" if shock mount center to center dimension is less than 33 3/4"
Will not fit GT40 "P" head

Mercury - Cougar

EMISSION AUTO STD TUBE COLLECTOR PORT
YEARS ENGINES CODE A/C P/B P/S COL FLR COL FLR SIZE (in.) SIZE (in.) SHAPE
67 - 73 260-302 Y Y Y Y Y N Y 1 5/8 3 SAP
Header installation requires the use of the 1965-66 Non Hi-Po V8 clutch equalizer bar
Lakewood bell housings require clearancing for header tubes
Mid length design for maximum ground clearance
Must use 66 1/2 or later frame brackets (approx. 1" higher than 65 and early 66 style)
Use recommended C5ZZ16A052E "export brace" if shock mount center to center dimension is less than 33 3/4"
Will not fit GT40 "P" head

Applications and Footnotes

Ford - Mustang

YEARS 64 - 73
ENGINES 260-302
EMISSION CODE
A/C Y
P/B Y
P/S Y
AUTO COL Y
AUTO FLR Y
STD COL N
STD FLR Y
TUBE SIZE (in.) 1 5/8
COLLECTOR SIZE (in.) 3
PORT SHAPE SAP
Header installation requires the use of the 1965-66 Non Hi-Po V8 clutch equalizer bar
Lakewood bell housings require clearancing for header tubes
Mid length design for maximum ground clearance
Must use 66 1/2 or later frame brackets (approx. 1" higher than 65 and early 66 style)
Use recommended C5ZZ16A052E "export brace" if shock mount center to center dimension is less than 33 3/4"
Will not fit GT40 "P" head

Mercury - Cougar

YEARS 67 - 73
ENGINES 260-302
EMISSION CODE
A/C Y
P/B Y
P/S Y
AUTO COL Y
AUTO FLR Y
STD COL N
STD FLR Y
TUBE SIZE (in.) 1 5/8
COLLECTOR SIZE (in.) 3
PORT SHAPE SAP
Header installation requires the use of the 1965-66 Non Hi-Po V8 clutch equalizer bar
Lakewood bell housings require clearancing for header tubes
Mid length design for maximum ground clearance
Must use 66 1/2 or later frame brackets (approx. 1" higher than 65 and early 66 style)
Use recommended C5ZZ16A052E "export brace" if shock mount center to center dimension is less than 33 3/4"
Will not fit GT40 "P" head

Key for abbreviations and acronyms
2V Two valve cylinder head
DP Dual Smog Pump (emissions device)
PSIG Pounds Per Square Inch Gauge
3V Three valve cylinder head
E.O. Executive Order
RD Round Port
4V Four valve cylinder head
EGR Exhaust Gas Recirculation (emissions device)
REC Rectangle Port
A/C Air Conditioning
FLR Floor
SAP Same As (cylinder head) Port
AUTO Automatice Transmission
MCTBC Metallic Ceramic Thermal Barrier Coating
SP Single Smog Pump (emissions device)
COL Column shift
OVL Oval Port
STD Standard Transmission
COLL Collector
P/B Power Brakes
T.P.I. Tuned Port Injection
DIA Diameter
P/S Power Steering

Emissions Code Key

The application guide above specifies which Emissions Code applies to this part. Doug's Headers uses a voluntary product identification program whereby all mission-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) "E.O" (Executive Order) Exemption, or is considered a Direct Replacement or Consolidated Replacement part. It is 50 State Legal when installed on the appropriate vehicle per the Manufacturer Application guide and Installation Instructions

This product is Legal for use on 1974 and older non catalyst equipped vehicles and is considered a "replacement part" per California Air Resources Board regulations, as long as ALL emissions sensitive components are retained, including A.I.R., EGR, Heat Risers etc. Failure to retain any of these components, or use on any 1975 or newer catalytic converter equipped car would render this product Illegal for Street or Off Highway Use in California, or in states that have adopted California Emissions regulations and may only be used for Closed Course Competition.

This product is Not legal for Street or Off Highway use in California or in states that have adopted California Emissions Regulations and is only intended for Closed Course Competition use, except 1965 and Older US manufactured California Certified vehicles, 1967 or older US manufactured Federally Certified vehicles, or 1967 and older Foreign manufactured vehicles which may have any aftermarket add-on or modified part installed as long as the vehicle can still meet the tailpipe emission standards for the year of the vehicle and retain any original or retrofit crankcase control (PCV) devices and NOx device required for the year of the vehicle.

Additional Information

Doug's PASSENGER CAR HEADERS Mid Length 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
Instruction Manual
Instruction Manual

Download PDF

Reviews

Doug's Headers - D665

Doug's Headers D665 1 5/8" 4-Tube Shorty Header Ford Mustang Small Block Ford 64-73 Metallic Ceramic Coating

Doug's Headers D665 1 5/8" 4-Tube Shorty Header Ford Mustang Small Block Ford 64-73 Metallic Ceramic Coating

Part Number: D665 / UPC 694342519162
$819.95
$819.95 $799.99

Part Number: D665 / UPC 694342519162
  • Free shipping on $99+ orders in lower 48 states
  • 90-day return policy
  • We’re here to help! Call us on 909-599-5955
Emissions code

Emissions Code

Continue Reading to Understand Emissions Codes
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Product Info
  • 3/8" Thick machined flanges... no warping
  • CNC mandrel bent tubes... accurate fit & better flow
  • Mid length headers provide improved groungd clearance for popular muscle cars and street rods
  • 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

Ford - Mustang

    EMISSION       AUTO STD TUBE COLLECTOR PORT
YEARS ENGINES CODE A/C P/B P/S COL FLR COL FLR SIZE (in.) SIZE (in.) SHAPE
64 - 73 260-302 Y Y Y Y Y N Y 1 5/8 3 SAP
Header installation requires the use of the 1965-66 Non Hi-Po V8 clutch equalizer bar
Lakewood bell housings require clearancing for header tubes
Mid length design for maximum ground clearance
Must use 66 1/2 or later frame brackets (approx. 1" higher than 65 and early 66 style)
Use recommended C5ZZ16A052E "export brace" if shock mount center to center dimension is less than 33 3/4"
Will not fit GT40 "P" head

Mercury - Cougar

    EMISSION       AUTO STD TUBE COLLECTOR PORT
YEARS ENGINES CODE A/C P/B P/S COL FLR COL FLR SIZE (in.) SIZE (in.) SHAPE
67 - 73 260-302 Y Y Y Y Y N Y 1 5/8 3 SAP
Header installation requires the use of the 1965-66 Non Hi-Po V8 clutch equalizer bar
Lakewood bell housings require clearancing for header tubes
Mid length design for maximum ground clearance
Must use 66 1/2 or later frame brackets (approx. 1" higher than 65 and early 66 style)
Use recommended C5ZZ16A052E "export brace" if shock mount center to center dimension is less than 33 3/4"
Will not fit GT40 "P" head

 

 

Applications and Footnotes

Ford - Mustang

YEARS 64 - 73
ENGINES 260-302
EMISSION CODE
A/C Y
P/B Y
P/S Y
AUTO COL Y
AUTO FLR Y
STD COL N
STD FLR Y
TUBE SIZE (in.) 1 5/8
COLLECTOR SIZE (in.) 3
PORT SHAPE SAP
Header installation requires the use of the 1965-66 Non Hi-Po V8 clutch equalizer bar
Lakewood bell housings require clearancing for header tubes
Mid length design for maximum ground clearance
Must use 66 1/2 or later frame brackets (approx. 1" higher than 65 and early 66 style)
Use recommended C5ZZ16A052E "export brace" if shock mount center to center dimension is less than 33 3/4"
Will not fit GT40 "P" head

Mercury - Cougar

YEARS 67 - 73
ENGINES 260-302
EMISSION CODE
A/C Y
P/B Y
P/S Y
AUTO COL Y
AUTO FLR Y
STD COL N
STD FLR Y
TUBE SIZE (in.) 1 5/8
COLLECTOR SIZE (in.) 3
PORT SHAPE SAP
Header installation requires the use of the 1965-66 Non Hi-Po V8 clutch equalizer bar
Lakewood bell housings require clearancing for header tubes
Mid length design for maximum ground clearance
Must use 66 1/2 or later frame brackets (approx. 1" higher than 65 and early 66 style)
Use recommended C5ZZ16A052E "export brace" if shock mount center to center dimension is less than 33 3/4"
Will not fit GT40 "P" head

 

 

Key for abbreviations and acronyms
2V Two valve cylinder head
DP Dual Smog Pump (emissions device)
PSIG Pounds Per Square Inch Gauge
3V Three valve cylinder head
E.O. Executive Order
RD Round Port
4V Four valve cylinder head
EGR Exhaust Gas Recirculation (emissions device)
REC Rectangle Port
A/C Air Conditioning
FLR Floor
SAP Same As (cylinder head) Port
AUTO Automatice Transmission
MCTBC Metallic Ceramic Thermal Barrier Coating
SP Single Smog Pump (emissions device)
COL Column shift
OVL Oval Port
STD Standard Transmission
COLL Collector
P/B Power Brakes
T.P.I. Tuned Port Injection
DIA Diameter
P/S Power Steering

 

 

Highlights
  • 3/8" Thick machined flanges... no warping
  • CNC mandrel bent tubes... accurate fit & better flow
  • Mid length headers provide improved groungd clearance for popular muscle cars and street rods
  • 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

Ford - Mustang

EMISSION AUTO STD TUBE COLLECTOR PORT
YEARS ENGINES CODE A/C P/B P/S COL FLR COL FLR SIZE (in.) SIZE (in.) SHAPE
64 - 73 260-302 Y Y Y Y Y N Y 1 5/8 3 SAP
Header installation requires the use of the 1965-66 Non Hi-Po V8 clutch equalizer bar
Lakewood bell housings require clearancing for header tubes
Mid length design for maximum ground clearance
Must use 66 1/2 or later frame brackets (approx. 1" higher than 65 and early 66 style)
Use recommended C5ZZ16A052E "export brace" if shock mount center to center dimension is less than 33 3/4"
Will not fit GT40 "P" head

Mercury - Cougar

EMISSION AUTO STD TUBE COLLECTOR PORT
YEARS ENGINES CODE A/C P/B P/S COL FLR COL FLR SIZE (in.) SIZE (in.) SHAPE
67 - 73 260-302 Y Y Y Y Y N Y 1 5/8 3 SAP
Header installation requires the use of the 1965-66 Non Hi-Po V8 clutch equalizer bar
Lakewood bell housings require clearancing for header tubes
Mid length design for maximum ground clearance
Must use 66 1/2 or later frame brackets (approx. 1" higher than 65 and early 66 style)
Use recommended C5ZZ16A052E "export brace" if shock mount center to center dimension is less than 33 3/4"
Will not fit GT40 "P" head

Applications and Footnotes

Ford - Mustang

YEARS 64 - 73
ENGINES 260-302
EMISSION CODE
A/C Y
P/B Y
P/S Y
AUTO COL Y
AUTO FLR Y
STD COL N
STD FLR Y
TUBE SIZE (in.) 1 5/8
COLLECTOR SIZE (in.) 3
PORT SHAPE SAP
Header installation requires the use of the 1965-66 Non Hi-Po V8 clutch equalizer bar
Lakewood bell housings require clearancing for header tubes
Mid length design for maximum ground clearance
Must use 66 1/2 or later frame brackets (approx. 1" higher than 65 and early 66 style)
Use recommended C5ZZ16A052E "export brace" if shock mount center to center dimension is less than 33 3/4"
Will not fit GT40 "P" head

Mercury - Cougar

YEARS 67 - 73
ENGINES 260-302
EMISSION CODE
A/C Y
P/B Y
P/S Y
AUTO COL Y
AUTO FLR Y
STD COL N
STD FLR Y
TUBE SIZE (in.) 1 5/8
COLLECTOR SIZE (in.) 3
PORT SHAPE SAP
Header installation requires the use of the 1965-66 Non Hi-Po V8 clutch equalizer bar
Lakewood bell housings require clearancing for header tubes
Mid length design for maximum ground clearance
Must use 66 1/2 or later frame brackets (approx. 1" higher than 65 and early 66 style)
Use recommended C5ZZ16A052E "export brace" if shock mount center to center dimension is less than 33 3/4"
Will not fit GT40 "P" head

Key for abbreviations and acronyms
2V Two valve cylinder head
DP Dual Smog Pump (emissions device)
PSIG Pounds Per Square Inch Gauge
3V Three valve cylinder head
E.O. Executive Order
RD Round Port
4V Four valve cylinder head
EGR Exhaust Gas Recirculation (emissions device)
REC Rectangle Port
A/C Air Conditioning
FLR Floor
SAP Same As (cylinder head) Port
AUTO Automatice Transmission
MCTBC Metallic Ceramic Thermal Barrier Coating
SP Single Smog Pump (emissions device)
COL Column shift
OVL Oval Port
STD Standard Transmission
COLL Collector
P/B Power Brakes
T.P.I. Tuned Port Injection
DIA Diameter
P/S Power Steering

Emissions Code Key

The application guide above specifies which Emissions Code applies to this part. Doug's Headers uses a voluntary product identification program whereby all mission-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) "E.O" (Executive Order) Exemption, or is considered a Direct Replacement or Consolidated Replacement part. It is 50 State Legal when installed on the appropriate vehicle per the Manufacturer Application guide and Installation Instructions

This product is Legal for use on 1974 and older non catalyst equipped vehicles and is considered a "replacement part" per California Air Resources Board regulations, as long as ALL emissions sensitive components are retained, including A.I.R., EGR, Heat Risers etc. Failure to retain any of these components, or use on any 1975 or newer catalytic converter equipped car would render this product Illegal for Street or Off Highway Use in California, or in states that have adopted California Emissions regulations and may only be used for Closed Course Competition.

This product is Not legal for Street or Off Highway use in California or in states that have adopted California Emissions Regulations and is only intended for Closed Course Competition use, except 1965 and Older US manufactured California Certified vehicles, 1967 or older US manufactured Federally Certified vehicles, or 1967 and older Foreign manufactured vehicles which may have any aftermarket add-on or modified part installed as long as the vehicle can still meet the tailpipe emission standards for the year of the vehicle and retain any original or retrofit crankcase control (PCV) devices and NOx device required for the year of the vehicle.

Additional Information

Doug's PASSENGER CAR HEADERS Mid Length 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
Instruction Manual
Instruction Manual

Download PDF

Reviews

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