BluePrint Builder Series 400/500HP Standard Edition EFI Crate Engine and 700R4 Transmission Combos B400FK700

BluePrint's biggest small-block Standard Edition steps up to 400 cubic inches: 500 horsepower, 510 pound-feet, 10.3:1 compression, fuel injected, and sold matched to a 700R4 automatic transmission as one package.

Forged bottom end

Forged pistons turn on a forged I-beam, 5.700-inch connecting rod, bolted at 150,000 psi, riding a forged crankshaft with a 3.750-inch stroke. The H8103 aluminum heads carry 2.080-inch intake and 1.600-inch exhaust valves over a hydraulic roller cam, with a raised exhaust port measuring 0.500 inch taller than the factory design. Bore comes in at 4.125 inches, on a block with four bolts per main and a one-piece rear seal.

Induction and transmission

Fuel injection here is self-contained, pump kit and all, feeding the dual-plane intake without needing a separate in-tank setup. The 700R4 ships with its torque converter already set to stall around 2,200-2,400 rpm, a weighted flexplate, and a starter in place; as with BluePrint's other 700R4 combos, the speedometer gear and its sender housing are left out for the builder to match against their own gearing. Polished hardware up front covers the compressor and power-steering mounts. Fits Chevrolet applications 1970 through 1980; not designed for EGR compatibility.

How does this compare to BluePrint's smaller small-block Standard Edition combo? This 400 is the bigger of the two, with more displacement and a forged crank and pistons rather than a cast rotating assembly.