A12 was Chrysler's mid-1969 muscle hammer: take the cheapest B-body two-door coupe (Dodge Coronet Super Bee or Plymouth Road Runner), bolt in the brand-new 440 Six Barrel intake (three Holley 2-bbls on an Edelbrock Streetmaster manifold) on top of the 440 RB block, top it with a black fiberglass lift-off hood with four chrome NASCAR pins, throw out the wheel covers and hubcaps in favor of bare 15×6 steel wheels, mandatory A33 Track Pak with 4.10 Sure-Grip rear, manual TorqueFlite or 4-speed, no power steering, no power brakes, no air. List price under $3,500.
About 2,025 cars built across both badges (roughly 1,412 Super Bees + 613 Road Runners) over a four-month production window May–August 1969. Every A12 carries the engine code M (the Six-Barrel was M-coded in 1969 only — from 1970 the same engine became V-code with a steel hood). The lift-off hood is the visual signature; the lack of any chrome on the wheels is the giveaway from a distance.
From 1970 the package was discontinued — the 440 Six-Pack continued as a regular option but with a steel hood and conventional latching, no longer A12. So A12 on a fender tag outside 1969 is almost certainly a misread or a swapped tag. Plenum flags this.