Description
1405 600 CFM Performer Carburetor — Manual Choke, 4-Barrel Square Bore
The iFJF 1405 Performer carburetor is a precision-engineered 600 CFM 4-barrel square bore carburetor designed as a direct replacement and performance upgrade for the Edelbrock 1405. Ideal for small-block and mild big-block V8 engines from 350 to 450+ cubic inches, this manual choke carburetor delivers crisp throttle response, consistent fuel metering, and trouble-free operation — whether you're cruising on the street, towing, or hitting the track.
Key Features
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600 CFM Flow Rating: Optimized for street performance and mild race applications on 350-454ci V8 engines. Ideal airflow for dual-plane intake manifolds.
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Manual Choke: Driver-controlled cold-start enrichment — eliminates the complexity of electric choke wiring and provides positive choke control in all weather conditions.
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4-Barrel Square Bore Design: Direct bolt-on for Edelbrock Performer, Performer RPM, and most OEM square bore intake manifolds. No adapter required.
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Air Valve Secondary: Vacuum-operated secondary air valve opens progressively based on engine demand — no bog, no hesitation, just smooth power delivery.
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No EGR Provision: Clean, simple design without EGR ports — ideal for off-road, racing, or pre-emissions vehicles. For off-road and racing use only where emissions equipment is not required.
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Tunable Without Disassembly: Externally adjustable idle mixture screws and easily accessible metering rods and jets enable tuning without removing the carburetor from the manifold.
Technical Specifications
| Specification |
Value |
| CFM Rating |
600 CFM @ 1.5 inHg |
| Barrel Configuration |
4-Barrel, Square Bore |
| Choke Type |
Manual (cable-operated) |
| Secondary Type |
Vacuum-Controlled Air Valve |
| Fuel Inlet |
Single 5/8"-20 UNF |
| Throttle Bore Diameter |
Primary 1-7/16", Secondary 1-11/16" |
| Mounting Flange |
Square Bore (5-1/8" x 5-5/8") |
| Finish |
Satin Silver / Natural Aluminum |
| Recommended Fuel Pressure |
5.5 psi maximum (regulator recommended) |
Compatibility Guide
| Engine Family |
Displacement |
Application Notes |
| Small Block Chevy |
305-400 ci |
Excellent match for mild 350 builds with dual-plane intake |
| Small Block Ford |
289-351 ci |
Ideal for 302/351W street performance |
| Big Block Chevy |
396-454 ci |
Suitable for mild street BBC — may be slightly small for high-RPM 454+ |
| AMC V8 |
304-401 ci |
Popular upgrade for AMC 360/401 |
| Chrysler LA/Magnum |
318-360 ci |
Requires square bore intake or adapter |
Why Choose the 1405 Manual Choke Carburetor?
The manual choke design offers several advantages over automatic chokes for performance applications. You get positive, immediate choke control without waiting for an electric element to heat up — essential for engines with aggressive camshafts that need precise cold-start enrichment. The manual cable setup also eliminates a potential failure point (burned-out electric choke) and reduces electrical load on your charging system. For race cars, off-road vehicles, and hot rods where simplicity is key, the manual choke 1405 is the go-to choice.
Tuning Guide
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Idle Mixture: Start with both idle mixture screws 1.5 turns out. Warm engine fully. Adjust each screw for highest vacuum reading, then back out 1/8 turn for best idle quality.
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Idle Speed: Set curb idle to 700-800 RPM (manual trans) or 650-750 RPM (auto in drive). Verify timing is set correctly before adjusting carb.
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Metering Rods & Jets: Factory calibration works well for most 350-400ci street engines. For altitude (>5,000 ft), step down one jet size. For high-compression builds, step up one rod size richer.
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Secondary Air Valve: Adjust pre-load spring tension via the set screw on the passenger side. Lighter tension = earlier secondary opening. Too light = bog. Too heavy = sluggish top end.
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Float Level: Fuel level should be 7/16" from the top of the float bowl with the engine idling. Adjust via the external needle & seat assembly — no bowl removal needed.
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Fuel Pressure: Edelbrock-style carbs are sensitive to fuel pressure. Use a regulator set to 5.5 psi maximum. Higher pressure will force the needle off the seat and flood the engine.
Frequently Asked Questions
Q: What's the difference between the 1405 and 1406 carburetors?
A: The 1405 uses a manual choke (cable-operated), while the 1406 uses an electric choke (automatic, 12V). The 1405 is preferred for race cars, off-road vehicles, and applications where the driver wants full choke control. The 1406 is better for daily drivers and street cars where automatic cold-start convenience is desired.
Q: Do I need a square bore to spread bore adapter?
A: If your intake manifold is a spread bore design (Q-jet pattern), yes. If it's a square bore (Holley/Edelbrock pattern), no. Most aftermarket dual-plane intakes (Edelbrock Performer, Weiand Action Plus, etc.) are square bore and accept this carburetor directly.
Q: Will this carburetor work with my stock hood?
A: The 1405/1406 has a relatively low profile compared to Holley double pumpers and Dominator carbs. In most applications with a stock or mild drop-base air cleaner, hood clearance is not an issue. Measure from the intake manifold carb pad to the hood for verification.
Q: What fuel pump do I need?
A: A standard mechanical fuel pump (5-7 psi) with a regulator set to 5.5 psi maximum is ideal. Electric pumps must also be regulated. Do NOT exceed 6.0 psi — these carbs are highly sensitive to over-pressurization.
Q: Is this carburetor emissions-legal for street use?
A: This carburetor does not have EGR provisions and is intended for off-road, racing, and pre-emissions (pre-1975) vehicles. Check your local emissions regulations before installing on a street-driven vehicle.
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