M20 / M21 ● Confirmed

Pontiac · Regular Production Option

4-speed / close-ratio 4-speed

Years 1975 Models 1

Documented applications

Firebird / Trans Am →

• 1975 ● Confirmed

This page aggregates every documented appearance of M20 / M21 in the Pontiac reference. Confidence and citations are shown per application — the same code can be better documented in one year than another.