What is a 'long block'?

A 'long block' includes all of the components for a short block, plus:

• the head(s) (the 'top half' of the engine, where the valves are);
• oil pan;
• camshafts;
• valves, lifters, and springs; and
• intake or intake manifold.

A long block is not a complete engine. Missing parts include carburators or injectors, exhaust manifold, turbocharger(a) or supercharger(s) (if any), intercooler(s) (if any), and so forth.