General Motors option code

M12

M12: a General Motors factory option code reused for more than one part across 1964–1973 and 2 models — see the table for what it named each year, with installs and price where a source states them.

General Motors reused this code for more than one part over the years — read the "as named that year" column for what it meant on each row rather than assuming one meaning throughout.

2 models · 4 model years · 3 sources

Dealer information sheet headed "A Hot New Number... Olds 4-4-2" with a black 1964 F-85 coupe and a list of 4-4-2 features
1964 Oldsmobile F-85 4-4-2, from an Oldsmobile "Product Selling Information" sheet for salesmen

Every sourced appearance

Year Model As named that year Price Installs
1964 Oldsmobile Cutlass, 4-4-2 and Hurst/Olds Transmission, floor-shift 3-speed synchromesh RPO $43.04 Unknown
1971 Pontiac Firebird and Trans Am 3 Speed Manual Transmission, Floor Mounted Shifter. (sales code 35B) RPO/UPC $10.53 Unknown
1972 Pontiac Firebird and Trans Am 3 Speed Manual Transmission, Floor Mounted Shifter. (sales code 35B) RPO/UPC $10 Unknown
1973 Pontiac Firebird and Trans Am 3 Speed Manual Transmission, Floor Mounted Shifter. (sales code 36B) RPO/UPC Unknown Unknown

Every row traces to the source it links from on that model's own year page; this table only collects them in one place.