Engine Block Terminology

What’s the difference between a small block and a big block? How about a short block and a long block?

Short Block: An engine WITHOUT the head(s). Usually includes the crankshaft, camshaft, and pistons.

Long Block: An engine WITH the head(s). Usually does not include the oil pan, valve covers, and manifolds.

Small Block: The smaller of a manufacturers two series of engines. In the case of Chevy, the small block includes the 262, 265, 267, 283, 302, 305, 307, 327, 350, and 400.

Big Block: The larger of a manufacturers two series of engines. In the case of Chevy, the 366, 396, 402, 427, and 454.

Notice the overlap of small and big block displacements. Note also that a small block can be a long block. The terms define different characteristics of the engine.