BluePrint Engines B400K700 SBC 400/500HP with 700R4, Carbureted

This carbureted 400 runs the same forged crankshaft and forged pistons as BluePrint's EFI 400, feeding a Holley 750 CFM carburetor on a dual-plane intake instead of fuel injection. The 700R4 automatic behind it runs a 10.3:1 compression ratio up front.

What it is built for

Pick this version if you prefer carburetor simplicity over electronic fuel injection while keeping the same forged-internals 400 and automatic drivetrain pairing. A polished front accessory drive and the same aluminum cylinder heads as BluePrint's EFI 400 are part of this long block too.

What to check before ordering

Converter stall is 2,200-2,400 rpm here, with the flexplate and starter already included in the package. Confirm carburetor linkage, throttle cable routing, and fuel line fittings suit your chassis before ordering, since this version has no electronic throttle body. This is classified as an engine-change part in California, so the installation needs to satisfy the Bureau of Automotive Repairs policy on engine swaps.

Common questions

What size carburetor does it use? A 750 CFM Holley on a dual-plane intake.

Is the ignition electronic? The long block includes its own distributor rather than a computer-controlled ignition module.

Is there a flywheel in this kit? No; a flexplate does the job for automatic transmissions like this one.

Are the cylinder heads aluminum? Yes, the same aluminum heads used on BluePrint's EFI 400.