K21 ◑ Single-source

Chevrolet · Regular Production Option

Engine controlled combustion system

Years 1963–79 Models 1

Documented applications

Impala / Full-Size →

• 1963–70s (varies) ◑ Single-source

This page aggregates every documented appearance of K21 in the Chevrolet reference. Confidence and citations are shown per application — the same code can be better documented in one year than another.