Offenhauser 6227HD Ford 240/300 Inline 6 Heat Delete Intake Manifold

Description

Offenhauser 6227HD Ford 240/300 Inline 6 Heat Delete Intake Manifold

 

 

The Offenhauser 6227HD Heat Delete Intake Manifold is the ideal solution for Ford 240–300 inline six owners running headers who want proven Offenhauser performance without unnecessary intake heat. Designed as a header-optimized version of our popular 6227C, the 6227HD delivers the same airflow, torque, and horsepower gains—while eliminating the heat provisions many header applications don’t need or want.

This high-performance C-Series intake bridges the gap between stock and full race setups, offering strong mid- and upper-RPM power with a broad, street-friendly powerband from approximately 2,500 RPM to over 7,000 RPM. On stock Ford 240–300 engines, gains of up to 70 horsepower are possible, with even larger increases when paired with headers, camshaft upgrades, and proper tuning.

Unlike the 6227C, the 6227HD features a true “Heat Delete” design—no heat crossover or heat riser on the bottom of the manifold. This improves header clearance and eliminates the extra time and expense of removing heat provisions yourself. It’s a cleaner, purpose-built solution for modern performance builds.

Key Features

• Heat Delete design optimized for header applications
• Same proven performance and airflow as the 6227C
• Broad powerband with strong mid- and upper-RPM torque
• Improves throttle response and overall engine efficiency
• Cleaner installation and improved header clearance
• Ideal for street performance and competition use

Carburetor Compatibility

• Accepts Carter or Holley standard-bore square-flange 4-barrel carburetors
• Recommended carb size: 500 CFM and larger
• Holley 2300 series carbs may be used for competition with an adapter
• Carbs clear the C-Series design without modification
• Offenhauser universal linkage kit recommended for most installations

Engine Fitment

• Ford 240 / 300 Inline 6 engines
• Commonly listed as “through 1981,” but physically compatible with most cylinder heads through the late 1980s and often into the early 1990s
• Minor considerations such as water passage plugs or linkage setup may be required on later engines

Header Compatibility Notes

• Designed for use with headers
• Hedman headers are strongly recommended for best fit
• Hooker headers are commonly used and generally compatible
• Clifford headers are not recommended (designed for Clifford intakes only)
• Borla headers do not fit due to clearance issues
• Proper header installation kits with spacers and clamps are recommended, especially on 1981+ engines
• Recommended exhaust gasket: Remflex Header Gasket #3005

If you’re running headers and want maximum performance without unnecessary intake heat, the **Offenhauser 6227HD Heat Delete Intake Manifold** delivers legendary Offenhauser power with a cleaner, smarter installation—straight out of the box.