Ford Mustang 1964-1966 260 289 302 Windsor V8 RHD Advance Exhaust Headers A55

Advance A55 headers (extractors) are designed for right-hand-drive Ford Mustang 1964½-1966 models fitted with the 260, 289 or 302 Windsor V8 engine.

Manufactured in Australia from mild steel, A55 features a mandrel-bent Tri-Y design with 1½" primary pipes, 1¾" secondary pipes and 2" outlets. The Tri-Y configuration is well suited to street-driven Windsor V8 engines where strong usable torque and responsive performance are important.

IMPORTANT: A55 is the RIGHT-HAND-DRIVE application. It fits automatic and hydraulic-clutch manual applications but will NOT fit a mechanical clutch or GT40 cylinder heads.

Fits ram-type power steering.

Bolts and gaskets included.

Please check availability and current lead time before ordering.

Key Features

• Suits Ford Mustang 1964½-1966
• Suits right-hand-drive vehicles
• Suits 260ci Windsor V8
• Suits 289ci Windsor V8
• Suits 302ci Windsor V8 installations
• Tri-Y header design
• Mandrel-bent mild steel construction
• 1½" (38mm) primary pipes
• 1¾" (44mm) secondary pipes
• 2" (51mm) outlets
• Fits automatic transmission
• Fits hydraulic-clutch manual applications
• Fits ram-type power steering
• Bolts and gaskets included
• Australian Made

Construction

Advance A55 headers are manufactured from mild steel using mandrel-bent tubing and a Tri-Y pipe configuration.

The header dimensions are 1½" (38mm) primaries, 1¾" (44mm) secondaries and 2" (51mm) outlets.

Additional Options

Please contact Best Mufflers for advice on compatible exhaust components and installation parts for your early Mustang Windsor V8.

Vehicle Fitment

• Make: Ford
• Model: Mustang
• Year Range: 1964½-1966
• Engine: 260ci Windsor V8
• Engine: 289ci Windsor V8
• Engine: 302ci Windsor V8
• Steering Position: Right-hand drive
• Transmission: Automatic or hydraulic-clutch manual
• Power Steering: Fits ram-type power steering

Engine Note: The early Mustang was factory available with the 260 and 289 small-block Ford V8. The 302 Windsor is also specifically included in the current A55 header application, making A55 suitable for applicable early Mustangs that have subsequently been fitted with a 302 Windsor.

Header Specifications

• Part Number: A55
• Brand: Advance Headers
• Design: Tri-Y
• Material: Mild steel
• Pipe Forming: Mandrel bent
• Primary Pipe: 1½" / approximately 38mm
• Secondary Pipe: 1¾" / approximately 44mm
• Outlet: 2" / approximately 51mm
• Steering Position: RHD
• Manufacture: Australian Made

Fitment Notes

RIGHT-HAND-DRIVE APPLICATION: A55 is the Advance header application for right-hand-drive 1964½-1966 Mustangs.

Manual Transmission: A55 will fit a manual vehicle using a hydraulic clutch. It will not fit the original mechanical clutch linkage.

Automatic Transmission: A55 is suitable for applicable automatic-transmission vehicles.

Power Steering: A55 is listed as suitable for the early Mustang ram-type power-steering system.

GT40 Cylinder Heads: A55 is specifically listed as NOT suitable for GT40 cylinder heads.

Left-Hand Drive: Do not use A55 as the default header for a left-hand-drive Mustang. Advance lists the separate A55L for left-hand-drive vehicles, with the current A55L application specified for automatic transmission. Please contact us for the correct LHD application.

Early Mustangs are now frequently modified with different engines, transmissions, clutch systems, steering conversions and cylinder heads. Please confirm these details before ordering.

What's Included

• Advance A55 header assembly
• Header bolts
• Header gaskets

Recommended With

When installing the headers, inspect the existing exhaust system, engine mounts, transmission mounts and exhaust hardware. Contact Best Mufflers if you require advice on completing the exhaust system from the A55 outlets.

Why Good Headers & Exhaust Systems Matter

At 4,000 rpm, a 289ci / 4.7L Windsor V8 theoretically draws approximately 9,400 litres of intake air per minute at 100% volumetric efficiency. Using an illustrative hot exhaust volume at approximately 600°C, this represents around 28,200 litres of exhaust gas per minute.

A 302ci / 4.9L Windsor V8 theoretically draws approximately 9,800 litres of intake air per minute at 4,000 rpm and expels around 29,400 litres of hot exhaust gas per minute using the same illustrative calculation.

A well-designed header and exhaust system helps manage this high gas flow efficiently, reducing restriction and improving exhaust scavenging, torque, throttle response and engine performance.

Installation Tips

Professional installation is recommended, particularly on converted right-hand-drive Mustangs where steering and clutch configurations can vary.

Before installation, confirm clearance around the steering system, clutch mechanism, starter motor, transmission, engine mounts and spark plugs.

Lubricate threaded fasteners with WD-40 or a similar penetrating lubricant before removal to assist with easier removal and installation.

After installation and several heat cycles, inspect the exhaust system for leaks and recheck accessible fasteners where appropriate.

Warranty & Compliance

Installation should comply with applicable Australian state or territory requirements relating to exhaust noise and vehicle modifications.

FAQ

What Mustang does Advance A55 fit?
A55 is designed for right-hand-drive Ford Mustang 1964½-1966 models fitted with a 260, 289 or 302 Windsor V8.

Does A55 fit the 289 Windsor?
Yes. The 289 Windsor V8 is one of the primary A55 applications.

Does A55 fit a 302 Windsor conversion?
Yes. Current Advance application information specifically includes the 302 Windsor in the A55 application.

Does A55 fit a manual Mustang?
Yes, but only with a suitable hydraulic clutch. A55 will not fit a mechanical clutch.

Does A55 fit an automatic Mustang?
Yes. A55 is listed as suitable for applicable automatic-transmission vehicles.

Does A55 fit power steering?
Yes. A55 is listed as suitable for the early Mustang ram-type power-steering system.

Does A55 fit GT40 heads?
No. Current Advance application information specifically states that the A55 will not fit GT40 cylinder heads.

Does A55 fit a left-hand-drive Mustang?
A55 is the right-hand-drive application. Advance lists a separate A55L for left-hand-drive vehicles, currently specified for automatic transmission. Please contact us before ordering for an LHD Mustang.

What size are the A55 headers?
A55 uses 1½" (38mm) primary pipes, 1¾" (44mm) secondary pipes and 2" (51mm) outlets.

Are the headers mandrel bent?
Yes. Current Advance A55 product information specifies mandrel-bent mild steel construction.

Are bolts and gaskets included?
Yes. The supplied A55 product information specifies that bolts and gaskets are included.

Can I pick up from the store?
Yes. Pick up is available but must be pre-arranged before collection.

How much is freight?
Freight varies depending on your delivery location and where stock is available. Please contact us for freight charges before ordering. Where possible, we can arrange dispatch from the nearest available product location to help reduce freight costs and delivery times.

Do you ship to the USA?
Yes. Best Mufflers regularly ships exhaust systems and exhaust parts to customers throughout the United States.

Please note that import duties, tariffs, taxes, and customs clearance fees are not included in the product or shipping price. Once your order is processed and the applicable charges are calculated, we will send you a secure payment link to finalise the import duties and tariff charges before dispatch.

Customer Support

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