General Motors option code
M20
M20: a General Motors factory option code reused for more than one part across 1963–1977 and 9 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.
9 models · 15 model years · 18 sources
Every sourced appearance
| Year | Model | As named that year | Price | Installs |
|---|---|---|---|---|
| 1963 | Chevrolet Chevy II and Nova | 4-speed transmission (Nova 400) RPO | Unknown | Unknown |
| 1963 | Chevrolet Impala SS | Four-speed (close-ratio version M21) (12-16-1800) RPO | Unknown | Unknown |
| 1964 | Chevrolet Chevelle and Malibu SS | 4-speed transmission RPO | $188.30 | 30,566 Reported |
| 1964 | Chevrolet El Camino SS | 4-speed transmission RPO | $144.30 | Unknown |
| 1964 | Chevrolet Impala SS | Four-speed (V8 series) RPO | Unknown | Unknown |
| 1964 | Oldsmobile Cutlass, 4-4-2 and Hurst/Olds | Transmission, floor-shift 4-speed synchromesh RPO | $188.30 | Unknown |
| 1965 | Chevrolet Chevelle and Malibu SS | 4-speed transmission RPO | $188.30 | 39,092 Reported |
| 1965 | Chevrolet Chevy II and Nova | 4-speed Synchro-Mesh RPO | $184.30 | Unknown |
| 1965 | Oldsmobile Cutlass, 4-4-2 and Hurst/Olds | Transmission, 4-speed floor-shift RPO | $188.30 | Unknown |
| 1965 | Oldsmobile Starfire | Transmission, 4-speed floor-shift, Starfire models (deduct) RPO | $10.76 | Unknown |
| 1966 | Chevrolet Chevelle and Malibu SS | 4-speed wide range RPO | $184.35 | 73,022 Reported |
| 1966 | Chevrolet Chevy II and Nova | Four-speed manual transmission (V8: 114-116-11800) RPO | Unknown | Unknown |
| 1966 | Chevrolet El Camino SS | 4-speed wide-range transmission with L35, El Camino RPO | $188.30 | Unknown |
| 1966 | Oldsmobile Cutlass, 4-4-2 and Hurst/Olds | Transmission, fully synchronized 4-speed floor-shift (includes Hurst competition shifter) RPO | $184.31 | Unknown |
| 1966 | Oldsmobile Starfire | Transmission, fully synchronized 4-speed floor-shift RPO | $226.44 | Unknown |
| 1967 | Chevrolet Chevelle and Malibu SS | 4-speed wide range RPO | $184.35 | 48,354 Reported |
| 1967 | Chevrolet Chevy II and Nova | 4-speed transmission (3.11, 2.54 or 2.52:1 low; includes floor console with Nova SS) RPO | Unknown | Unknown |
| 1967 | Oldsmobile Cutlass, 4-4-2 and Hurst/Olds | Transmission, fully synchronized wide-ratio 4-speed floor-shift, Hurst competition shifter RPO | $184.31 | Unknown |
| 1968 | Chevrolet Chevelle and Malibu SS | 4-speed wide range RPO | $184.35 | 38,933 Reported |
| 1968 | Chevrolet Chevy II and Nova | 4-speed wide-range RPO | $184.35 | Unknown |
| 1968 | Oldsmobile Cutlass, 4-4-2 and Hurst/Olds | Transmission, fully synchronized 4-speed floor-shift wide-ratio, Hurst competition shifter (3.08, 3.23 or 3.42 axle required; G92 at extra cost; 3.42 standard) RPO | $184.31 | Unknown |
| 1969 | Chevrolet Chevelle and Malibu SS | 4-Speed Transmission RPO | $184.80 | 44,950 Reported |
| 1969 | Oldsmobile Cutlass, 4-4-2 and Hurst/Olds | Transmission, fully synchronized 4-speed floor-shift wide-ratio, Hurst competition shifter RPO | $184.80 | Unknown |
| 1970 | Chevrolet Chevelle and Malibu SS | 4-Speed Transmission RPO | $184.80 | 28,131 Reported |
| 1970 | Pontiac Firebird and Trans Am | 4 Speed Manual Transmission with Hurst Floor Shift (sales code 354) RPO/UPC | $195.36 | Unknown |
| 1971 | Chevrolet Chevelle and Malibu SS | 4-speed wide ratio RPO | $195.40 | 9,786 Reported |
| 1971 | Chevrolet Chevy II and Nova | 4-speed wide-range (Nova SS only) RPO | $195.40 | Unknown |
| 1971 | Oldsmobile Cutlass, 4-4-2 and Hurst/Olds | Transmission, 4-speed floor-shift wide-ratio, Hurst shifter RPO | $195.36 | Unknown |
| 1971 | Pontiac Firebird and Trans Am | 4 Speed Manual Transmission (sales code 35E) RPO/UPC | $205.97 | Unknown |
| 1972 | Chevrolet Chevelle and Malibu SS | 4-speed wide ratio RPO | $190 | 10,201 Reported |
| 1972 | Chevrolet Chevy II and Nova | 4-speed manual, wide ratio (L48 only) RPO | $200.65 | Unknown |
| 1972 | Pontiac Firebird and Trans Am | 4 Speed Manual Transmission (sales code 35E) RPO/UPC | $200 | Unknown |
| 1973 | Chevrolet Chevelle and Malibu SS | Wide-ratio 4-speed RPO | Unknown | 3,879 Reported |
| 1973 | Chevrolet Chevy II and Nova | 4-speed wide-range (requires Turbo-Fire 350-4) RPO | $190 | Unknown |
| 1973 | Pontiac Firebird and Trans Am | 4 Speed Manual Transmission (sales code 36E) RPO/UPC | $200 | Unknown |
| 1973 | Pontiac Grand Am | Four-speed manual (credit against standard automatic) RPO | $-46 | 1,058 Reported |
| 1973 | Pontiac Tempest and LeMans | 4-speed manual RPO | $190 | Unknown |
| 1974 | Chevrolet Chevy II and Nova | 4-speed wide-range RPO | $219 | Unknown |
| 1974 | Pontiac Firebird and Trans Am | 4 Speed Manual Transmission (Wide Ratio) (sales code 36E) RPO/UPC | $207 | Unknown |
| 1975 | Chevrolet Chevy II and Nova | 4-speed wide-range RPO | $219 | Unknown |
| 1975 | Pontiac Firebird and Trans Am | 4 Speed Manual Transmission (sales code 37E), Base and Esprit RPO/UPC | $219 | Unknown |
| 1976 | Chevrolet Chevy II and Nova | 4-speed wide-range manual RPO | $242 | Unknown |
| 1977 | Chevrolet Chevy II and Nova | 4-speed wide-range manual RPO | $252 | Unknown |
| 1977 | Pontiac Firebird and Trans Am | 4 Speed Manual Transmission, Firebird and Esprit RPO/UPC | $257 | 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.