PAFO107: Ford Small Block 5-bolt (1961-64 Block Years) to Ford Modular (ref.6R80) V8 or Ford 6-Bolt Small Block (AOD) V8 Automatic Transmission Adapter Kit

Ford Small Block 5-bolt (1961-64 Block Years) to Ford Modular (ref.6R80) V8 or Ford 6-Bolt Small Block (AOD) V8 Automatic Transmission Adapter Kit

ADDITIONAL PRODUCTS AVAILABLE:  If you are planning to purchase a Shift Controller option with your Adapter Kit, please see the link below to add the Throttle-position Sensor (TPS) Adapter Kit to suit your application.

TRANSMISSION STAND-ALONE CONTROLLERS & TPS ADAPTER KITS - ADD-TO-ORDER HERE

KIT OVERVIEW

This premium adapter kit is specifically engineered to allow the use of modern and widely available 6-bolt Small Block Ford (SBF) and Modular transmissions with early 5-bolt SBF engines produced between 1961 and early 1964.

These early SBF engines (commonly 221, 260, and early 289 CID) featured a unique 5-bolt bellhousing pattern that is not compatible with later Ford transmission designs—until now. This kit completely overcomes that limitation, expanding your drivetrain options significantly.

Whether you're restoring a classic, building a restomod, or just looking to upgrade drivability and reliability, this adapter kit is a game-changer.

Fits the Following Engines:

• 221 CID V8 (1962–63)
• 260 CID V8 (1962–64)
• 289 CID V8 (early 1963–mid 1964) with 5-bolt bellhousing

⚠️ Note: Ford switched to the 6-bolt bellhousing pattern mid-1964. Please verify your engine has a 5-bolt bellhousing before ordering.

Compatible Transmissions:

This kit allows you to bolt a wide range of modern Ford automatic transmissions behind your classic 5-bolt SBF engine, including:

• C4 (6-bolt case)
• C6
• AOD
• AODE
• 4R70W
• 4R75W
• 6R80 (Ford Modular)
• 10R80 (Ford Modular)

This is the only known adapter kit on the market that provides compatibility between the 5-bolt SBF and late-model Ford Modular transmissions like the 4R70W, 6R80, and 10R80, offering you unmatched flexibility for modern drivetrains.

What’s Included:

• CNC-machined Adapter Plate
• Crankshaft Spacer – ensures proper torque converter engagement
• High-Torque Mini Starter – properly indexed for this application
• Inspection Cover Plate – for easy maintenance
• Complete Hardware Kit – Grade 8 fasteners included

Key Features:

• Preserves OEM Flexplate: Retains the stock 164-tooth, 14.25" diameter flexplate with correct engine balance.
• Torque Converter Compatibility: Works with OEM torque converters using the standard 11.4" bolt pattern.

Why This Kit Matters:

Early SBF 5-bolt engines were only produced for a short time and have long suffered from a lack of modern transmission options. Traditional swaps required rare or obsolete bellhousings and transmissions, which limited performance and serviceability. This adapter opens the door to a new era of reliability, gearing, and drivability by letting you use late-model transmissions with overdrive, electronic shifting, and stronger internals.

Installation Notes:

• Professional installation is recommended.
• Transmission crossmember and driveshaft modifications may be required depending on the application.
  
• ECM tuning may be necessary for electronically controlled transmissions (AODE, 4R70W, 6R80, 10R80).

FAQ:

Q: How do I identify if I have a 5-bolt or 6-bolt SBF engine?
A: Count the number of bellhousing bolts at the rear of the engine. Early 5-bolt engines will have a narrow, five-bolt pattern, while later engines (mid-1964 and up) use a wider 6-bolt pattern. The casting date code on the engine block can also help confirm compatibility.

Q: Can I use my existing flexplate and converter?
A: Yes, you’ll retain the OEM 164-tooth flexplate with the proper engine balance and standard 11.4" converter bolt pattern.

Upgrade Your Classic Ford the Right Way

Don’t let outdated transmission options limit your project. With this 5-bolt SBF to 6-bolt/Modular transmission adapter kit, you’ll unlock a world of performance possibilities while keeping your vintage V8 at heart. Whether you’re building a sleeper or a show car, this kit gives your early SBF the drivetrain it deserves.

For additional questions, please Call, Text or Email us anytime at
608-640-2328 or Sales@Performanceadapters.com

Performance Adapters is not responsible for return shipping. Additional return information can be found in our policy pages. If you have any additional questions, please contact us call, text or email.