Edelbrock Carburetor Step-Up Spring Kit — Pack of 5, Color-Coded 3–8 Hg Tensions for Precise Throttle Tuning

Edelbrock 1464 is a five-spring, color-coded step-up spring kit designed to let you precisely tune carburetor throttle response and progression.

This kit includes one each of the 3 Hg (blue), 4 Hg (yellow), 5 Hg (orange), 7 Hg (pink) and 8 Hg (plain) steel step-up springs used to adjust the rate at which the carburetor opens as engine load changes. Each spring offers a different tension characteristic so you can match idle transition, part-throttle driveability and full-throttle response to your engine and vehicle setup. The springs are compact, vehicle-specific fitment items packaged in the United States and sold in packs of five for convenient swapping during tuning sessions.

How do these step-up springs affect carburetor behavior?

Step-up springs control how quickly the throttle plates or metering block advance when the throttle begins to open. Softer springs allow smoother, slower progression while stiffer springs produce quicker, more immediate throttle response. By choosing the correct spring you can reduce flat spots, eliminate hesitation and improve overall drivability.

• Includes five tension levels for gradual to aggressive progression.
• Color-coded for quick identification during tuning.
• Steel construction retains consistent spring rate under heat and use.

Which spring colors correspond to which tensions and when should I use each?

Each spring in the kit is marked by color and Hg rating to indicate relative stiffness. Use the lower Hg (blue 3 Hg) for the softest progression and the highest Hg (plain 8 Hg) for the firmest response; intermediate colors cover common tuning needs. Swap springs incrementally to find the balance between smooth part-throttle performance and crisp throttle entry.

• Blue — 3 Hg: softest, best for very smooth transitions.
• Yellow — 4 Hg and Orange — 5 Hg: mid-range options for typical street setups.
• Pink — 7 Hg and Plain — 8 Hg: stiffer choices for aggressive response.

How do I install or change a step-up spring on my carburetor?

Installation is straightforward for anyone familiar with basic carburetor linkage work: remove the air cleaner, access the throttle linkage, and replace the small spring where the accelerator pump or metering lever uses the step-up function. No special tools are required, though needle-nose pliers and a steady hand make the job quicker. Always test drive after each change to evaluate the effect before making additional swaps.

• Remove air cleaner to access the linkage area.
• Use pliers to unhook the old spring and attach the new color-coded spring.
• Test drive and adjust progressively—change one spring at a time.

Will these springs fit my vehicle and what should I check first?

The Edelbrock 1464 springs are designed for vehicle-specific carburetor applications; confirm compatibility with your carburetor model or Edelbrock parts list before ordering. Verify that your carburetor uses the same style of step-up spring location and tension system. If in doubt, consult your vehicle’s carburetor manual or contact Edelbrock technical support for fitment guidance.

• Check your carburetor model and Edelbrock compatibility charts.
• Inspect the existing spring mounting point for matching fit and length.
• Keep the original spring as a reference while testing new tensions.

Who is this for: The Edelbrock 1464 five-spring step-up kit is ideal for mechanics, performance tuners and DIY enthusiasts who want fine-grained control over carburetor throttle progression. It’s suitable for street machines, classic restorations and mild performance builds where dialed-in part-throttle behavior and smoother transitions matter. Because the springs are color-coded and supplied in a small pack, the kit is also handy for shops that perform frequent carburetor adjustments or restorations.