1968 Mustang Fuel Pump: What You Need to Know Before You Replace It

If you own a 1968 Ford Mustang, the fuel pump is a critical component that directly affects your car’s reliability and performance. Whether you have a 289, 302, 351W, or a big-block 390/428 engine, choosing the right fuel pump today can save you from being stranded tomorrow. The most common OEM-style fuel pump for the 1968 Mustang is the Carter button-top mechanical pump, which was factory-installed on many models. However, with modern fuel blends and ethanol content, many owners are upgrading to high-flow aftermarket pumps like KEMSO for improved durability and performance. Below, we break down everything you need to know about identifying, selecting, and replacing your 1968 Mustang fuel pump.

1. Identifying Your Original 1968 Mustang Fuel Pump

The factory fuel pump for a 1968 Mustang with a 289 or 302 engine is typically a Carter mechanical pump with a distinctive "button top" design. The original part number is C8OZ-9350-A, but it is more commonly identified by the Carter number 4567 . The pump body often has "Carter Made in USA" cast into the side, though some Canadian-made versions say "CAR BURE TER Made in Canada" .

For the 1968 Mustang with a 390 or 428 big-block (including the Cobra Jet), the correct pump is also a mechanical diaphragm-style unit with part number C7AZ-9350-CC or C7AZ-9350-A . These pumps flow around 120 gallons per hour at 5.5 to 7.5 psi, and they use heavy-duty diaphragms and high-speed springs .

Key identification points:

  • Button-top design: The pump housing has a rounded, button-like top.
  • Carter stamping: Look for "Carter" or "CAR BURE TER" on the side.
  • Date code: Stamped on the mounting flange, e.g., "7A9A" means January 9, 1967 .
  • Stamped "4567S": This is the service number for 289/302 applications .

2. Fuel Pump Options for Your 1968 Mustang

When you need a replacement, you have several choices. Here is a quick comparison:

1. OEM-Style Mechanical Pump
These are direct replacements that look like the original. They are available for both small-block (289/302/351W) and big-block (390/428) engines. They are all-new, not rebuilt, and come with a mounting gasket . Expect to pay between $50 and $150 for a quality unit.

2. High-Performance Mechanical Pump
Brands like Edelbrock offer mechanical pumps with higher flow rates—up to 110 gph at 6 psi—for the FE big-block engines . These are ideal if you have a modified engine.

3. In-Tank Electric Fuel Pump (EFI-Ready)
If you plan to convert to electronic fuel injection (EFI) or just want the reliability of an electric pump, you can install an in-tank module. For example, Stang-Aholics offers a 255 LPH high-flow pump module for 1964-1970 Mustangs, which supports up to 630 horsepower . This is a full replacement module that includes the pump, wiring harness, and filter sock. It costs around $229.99 .

4. High-Performance Aftermarket Pumps (like KEMSO)
KEMSO fuel pumps are designed as direct OEM replacements and offer over 20% more flow than stock pumps . They are built with high-quality materials, individually tested for performance, and come with a lifetime warranty. This is a smart upgrade for reliability and peace of mind .

3. Common Symptoms of a Failing Fuel Pump in a 1968 Mustang

  • Hard starting: The engine cranks but takes longer to fire.
  • Sputtering at high speeds: The car loses power when you accelerate, especially on the highway.
  • Stalling: The engine dies unexpectedly, especially after driving for a while.
  • Whining noise: A loud whine from the fuel tank area indicates wear .
  • Check engine light (if equipped): Many modern systems trigger a light if fuel pressure is irregular, but your 1968 Mustang likely has no such warning—so you must listen to your car .

4. Why You Should Replace the Fuel Filter and Gasket at the Same Time

When you replace the fuel pump, it is cheap insurance to replace other parts that wear out. This saves you from doing the job twice.

  • Fuel filter: Costs $10 to $50. A clogged filter strains the new pump and shortens its life .
  • Fuel pump gasket/O-ring: $5 to $30. Prevents vacuum leaks and fuel vapors.
  • Fuel lines and clamps: $20 to $100. Old rubber cracks and causes leaks.

Adding these items costs $50 to $150 extra but is well worth it .

5. How to Make Your New Fuel Pump Last Longer

  • Keep your tank at least a quarter full: The fuel cools and lubricates the pump. Running low frequently causes overheating and debris intake .
  • Change your fuel filter regularly: Every 30,000 to 50,000 miles is a good rule .
  • Use quality fuel: Cheap gas with high ethanol content can damage the pump over time. KEMSO pumps are designed to handle ethanol-blended fuels .
  • Don't ignore warning signs: A failing pump won't fix itself. Early replacement prevents being stranded .

6. Recommended Product: KEMSO Fuel Pump for Your 1968 Mustang

When it's time to replace your 1968 Mustang fuel pump, you want a part that is reliable, high-performance, and backed by a strong warranty. That is why KEMSO fuel pumps are an excellent choice for American drivers.

KEMSO fuel pumps are designed as direct OEM replacements, meaning they match the exact specifications of your vehicle's original pump. They are built with high-quality materials and undergo rigorous testing to ensure correct fuel pressure and flow rate. Each pump is individually tested for flow and performance before leaving the factory .

What sets KEMSO apart:

  • High Performance: Delivers 20-30% more fuel flow than stock pumps, which can improve throttle response and engine performance .
  • OEM Replacement: Direct bolt-in fit, no modifications needed. Just remove the old pump and install the new one .
  • Lifetime Warranty: Every KEMSO fuel pump comes with a lifetime warranty. If it ever fails due to a manufacturing defect, KEMSO replaces it for free .
  • Ethanol-Compatible: Designed to handle modern ethanol-blended fuels, ensuring long-term reliability .

Whether you drive a 1968 Mustang with a 289, 302, 351W, or a big-block 390/428, KEMSO has a fuel pump that fits. Visit their website to find the exact pump for your vehicle: https://www.kemsoracing.com/

Final Thoughts

Replacing the fuel pump on your 1968 Mustang is a straightforward job that can dramatically improve your car's reliability and performance. Whether you choose an original-style Carter pump or a high-performance upgrade, always pair it with a new fuel filter and gasket. For the best combination of performance, fit, and warranty protection, consider KEMSO fuel pumps. They are built to last, backed by a lifetime warranty, and designed to keep your classic Mustang running smoothly for years to come.

Visit https://www.kemsoracing.com/ today to find the perfect fuel pump for your 1968 Mustang.


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