1406 Carburetor Performer 600 CFM 4 Barrel Square Bore - Reliable Fit

In this review of the 1406 Carburetor for Performer 600 CFM, the bottom line is simple: it is aimed at DIY mechanics and classic V8 owners who need a ready-to-install replacement carb that restores strong throttle response without a big price tag. The reviewer found the unit delivers smooth acceleration out of the box, thanks to its bottom-feed primary venturi booster and two-step metering rods that ease circuit transition, reducing backfire risk and protecting power valves during tuning. It is not a computer-controlled application part, so buyers should confirm compatibility before ordering.

Key Features

• Two-Step Metering Rods: Helps smooth the transition between fuel circuits and minimize backfiring or power valve issues during acceleration.
• Bottom-Feed Primary Venturi Booster: Designed to improve throttle response and drivability by promoting stable fuel atomization in the primary bore.
• AFB-Style Square Bore Design: Fits a variety of performer-style intake manifolds for straightforward replacement on compatible engines.
• Non-Adjustable Secondary Air Valves: Simplifies setup for most street applications while providing predictable secondary engagement.
• Ready to Install Construction: Built from higher-grade materials and supplied new, intended to replace worn-out carburetor assemblies and restore performance.

Who It's For

This carburetor is best for owners of classic trucks and muscle cars such as Silverado, Corvette, Mustang, Mercury and GMC models running non-computer-controlled engines who want a cost-effective Performer-style 600 CFM replacement to regain acceleration and idle quality.

It is not suited for late-model vehicles with electronic fuel controls, Q-Jet systems from 1981 and later, or vehicles with AOD automatic overdrive from 1981 and later. Installers who expect detailed printed instructions should be prepared to consult online setup guides or professional tuning help.

Pros & Cons

Pros

• Good out-of-box functionality with apparent improved acceleration and smoother operation reported by users.
• Metering rods are replaceable for precise tuning, allowing better control over transition and midrange performance.
• Construction and materials feel solid for a replacement unit, offering value at the price point.

Cons

• Not compatible with computer-controlled engines or certain 1981-and-later GM systems, limiting fitment on some vehicles.
• Installation instructions are not included, so less-experienced installers will need to seek setup videos or guidance.

Specifications

Model Type	Performer 600 CFM 4-barrel AFB-style
Throttle Bore	Square bore 4-barrel
Air Valve	Non-adjustable electric choke secondary
Metering	Two-step metering rods, replaceable
Primary Venturi	Bottom-feed booster for smoother acceleration
Fitment Notes	Not for computer-controlled or certain 1981+ GM Q-Jet and AOD vehicles

Our Verdict

The 1406 Performer 600 CFM carburetor is a practical, budget-friendly replacement for older V8s needing restored throttle response and reliable transition control. It offers genuine tuning flexibility with replaceable metering rods and a bottom-feed primary design that improves drivability, making it a solid choice for DIY restorations and street-driven muscle cars, provided the vehicle uses a non-computer-controlled fuel system.

Frequently Asked Questions

Will this carburetor work on late-model computer-controlled engines?
No. This unit is not applicable to computer control applications or specific 1981-and-later GM Q-Jet and AOD configurations.

Are installation instructions included?
No. The package does not include instructions; installers should follow online setup videos or professional guidance for proper installation and tuning.

Can the metering rods be changed for tuning?
Yes. The carburetor uses easily changed metering rods to allow more precise tuning of the fuel transition characteristics.