BluePrint BP4002CT1 GM 400, Base Engine, Alum Heads, Roller Cam

This 400-cubic-inch base engine is BluePrint's largest small-block-based longblock outside the Builder Series combos: 500 horsepower and 510 pound-feet on 10.3:1 compression, shipped bare of a carburetor, intake, or distributor so the builder chooses their own induction.

Block and bottom end

Square and parallel decking, an align-honed main bearing bore, and sonic-tested cylinder walls define the new cast iron block, with bores finished on computer-controlled equipment to within .0002 inch of straightness and roundness. A forged crankshaft with a 3.750-inch stroke and 5.7-inch rods, fitted with 150,000-psi rod bolts, carries forged pistons, and the whole rotating assembly is balanced to within 2 grams before final assembly.

Valvetrain and heads

Aluminum heads with 64cc chambers use 2.08-inch, swirl-polished intake valves and 1.60-inch exhaust valves, with hardened retainers and springs, over a hydraulic roller camshaft and roller lifters. Valve covers top the heads, an oil pan and timing cover close out the bottom, brass freeze plugs are fitted, and BluePrint's own dyno paperwork ships with the engine, built and machined entirely in the USA. It's not designed for EGR compatibility and runs for 30 months or 50,000 miles of coverage, consistent with BluePrint's other longblocks.

Does this include a carburetor or distributor? No; this base engine ships without induction or ignition parts, so builders can choose their own setup.