Flowmaster introduces our new manifold downpipes for 1964-1966 Ford Mustangs with 289 V8 engines. These 2.50 in. mandrel bent 409S stainless steel pipes include the 2-bolt flanges, donut gaskets and donut sleeves. Works with kit #17273 and #817273. These downpipes are covered by Flowmaster's Lifetime Limited Warranty.
Features:
- Stainless Steel Construction
- Mandrel Bent Tubing
- Great Fit
- Lifetime Limited Warranty
Holley Performance Emission Code 3: This part is legal for sale and use on Uncontrolled (Non-Emissions Controlled) Vehicles and Racing Use Only Vehicles. The following vehicles are considered Uncontrolled (Non-Emissions Controlled) Vehicles: 1965 and older U.S. manufactured California Certified vehicles/1967 and older U.S. manufactured Federally Certified vehicles/1967 and older Foreign manufactured vehicle. The following vehicles are considered Racing Use Only Vehicles: Racing Use Only Vehicles are vehicles that are used exclusively for competition and that are not registered and that may never be used on the street. WARNING: It is against the law to install this part on an Emissions Controlled Vehicle. The following vehicles are considered Emissions Controlled Vehicles: 1966 and newer U.S. manufactured California Certified vehicles/1968 and newer U.S. manufactured Federally Certified vehicles/1968 and newer Foreign manufactured vehicle
Installation Notes:
Fits 1964-1966 Ford Mustangs with 289 V8 engines. Use With 817273 for complete manifolds-back exhaust system.

About Flowmaster
Manufacturer of performance exhaust systems, mufflers, performance air intakes, turbo boost modules, catalytic converters, race mufflers, headers and numerous exhaust accessories for late model cars, trucks, off-road, Jeeps, SUV’s, classic muscle cars, powersports vehicles and more. Flowmaster® gives you lots of exhaust choices with 12 designs of chambered mufflers, 3 styles of our exclusive “laminar-flow” mufflers and a new line of FlowFX “straight-through” performance mufflers, along with 5 sound categories of exhaust systems, giving you the customer, the power to custom tailor the sound of your vehicle whether you prefer mild, moderate or aggressive tones and sound levels. Since 1983, Flowmaster is the company you can trust, and has led the industry in offering only the best products you can buy for your vehicles.

Vehicle Fitment:
The Vehicle Fitment Guide is to be used as a general reference. The data has been provided by our suppliers and manufacturers and may contain errors or incorrect data. Always refer to a professional to verify correct fitment for your vehicle.
Make |
Model |
Years |
Engine |
Fitment Notes |
Ford |
Mustang |
1964 |
4.7L / 289 / V8 |
2 in. Inlet; 2.5 in. Outlet; Dual; 409 Stainless Steel;Legal On Non-Emissions Controlled Vehicles Or For Race Use |
Ford |
Mustang |
1965 |
4.7L / 289 / V8 |
2 in. Inlet; 2.5 in. Outlet; Dual; 409 Stainless Steel;Legal On Non-Emissions Controlled Vehicles Or For Race Use |
Ford |
Mustang |
1966 |
4.7L / 289 / V8 |
2 in. Inlet; 2.5 in. Outlet; Dual; 409 Stainless Steel;Legal On Non-Emissions Controlled Vehicles Or For Race Use |