BluePrint Engines BP4002 GM Small Block 400ci - Short Block

This BluePrint BP4002 is a 400ci GM small-block short block only, sold without cylinder heads, so the final power figure depends entirely on what heads, intake, and fuel system you pair with it. BluePrint's own dyno test, run with a Holley 850 CFM carburetor and HP8103 heads, produced 510 lb-ft of torque alongside 500 horsepower on a 10.3:1 compression ratio with 64cc heads, but BluePrint is clear that not every short block is individually dyno tested and that your own results will depend on your build.

Who this suits

This is aimed at a builder assembling a custom top end rather than someone who wants a dressed, ready-to-run engine. The short block itself uses a forged crankshaft, forged pistons, and a splayed 4-bolt main design, built for the loads a serious street or race combination can put on it.

What to check before ordering

Because this is a short block, plan separately for cylinder heads, an intake manifold, a fuel system, an oil pan, a timing cover, a water pump, and a harmonic balancer; none of those are included here. BluePrint specifies 91-octane fuel or better for this build. This part is restricted for California use: it is meant for competition or off-highway vehicles there, not for installation in vehicles licensed for public roads, and similar restrictions apply under federal and other states' laws.

Common questions

Does it include cylinder heads? No, this is a short block only; heads are on you to choose.

What rotating assembly does it use? A forged crankshaft and forged pistons with a 3.750-inch stroke and 5.700-inch rods.

Is every unit dyno tested? No; BluePrint's published figures come from one dyno combination, and actual output depends on the heads, intake, and fuel system used.