GM Muncie SM420 is a manual gearbox from GM Muncie. The Society has 13 vehicles on file with it, 13 with a source we opened and 0 still leads.
Chevrolet
| Vehicle | Years | Shift pattern | Gearbox source | Members |
|---|---|---|---|---|
| Chevrolet Light-duty trucks (Series 3100/3600 and successors), 4-speed Advance-Design Trucks with the optional floor-shift 4-speed [1] | 1948 | 4 speed, reverse bottom left | Corroborated | |
| Chevrolet Light-duty trucks (Series 3100/3600 and successors), 4-speed Advance-Design Trucks with the optional floor-shift 4-speed [2] | 1951 | 4 speed, reverse bottom left | Corroborated | |
| Chevrolet Light-duty trucks (Series 3100/3600 and successors), 4-speed Advance-Design Trucks with the optional floor-shift 4-speed [3] | 1952 | 4 speed, reverse bottom left | Corroborated | |
| Chevrolet Light-duty trucks (Series 3100/3600 and successors), 4-speed Advance-Design Trucks with the optional floor-shift 4-speed [4] | 1953 | 4 speed, reverse bottom left | Corroborated | |
| Chevrolet Light-duty trucks (Series 3100/3600 and successors), 4-speed Advance-Design Trucks with the optional floor-shift 4-speed [5] | 1954 | 4 speed, reverse bottom left | Corroborated | |
| Chevrolet Light-duty trucks (Series 3100/3600 and successors), 4-speed Task Force / Advance-Design Trucks with the optional floor-shift 4-speed [6] | 1955 | 4 speed, reverse bottom left | Corroborated | |
| Chevrolet Light-duty trucks (Series 3100/3600 and successors), 4-speed Task Force Trucks with the optional floor-shift 4-speed [7] | 1956 | 4 speed, reverse bottom left | Corroborated | |
| Chevrolet Light-duty trucks (Series 3100/3600 and successors), 4-speed Task Force Trucks with the optional floor-shift 4-speed [8] | 1957 | 4 speed, reverse bottom left | Corroborated | |
| Chevrolet Light-duty trucks (Series 3100/3600 and successors), 4-speed Task Force Trucks with the optional floor-shift 4-speed [9] | 1959 | 4 speed, reverse bottom left | Corroborated | |
| Chevrolet Light-duty trucks (Series 3100/3600 and successors), 4-speed C/K first generation Trucks with the optional floor-shift 4-speed [10] | 1960 | 4 speed, reverse bottom left | Corroborated | |
| Chevrolet Truck Apache / Task-Force era truck 4-speed floor lever [11] | 1960 | 4 speed, reverse bottom left | Corroborated | |
| Chevrolet Truck (1/2 and 3/4 ton) Task-Force era truck 4-speed floor lever [12] | 1954 | 4 speed, reverse bottom left | Corroborated |
Chevrolet and GMC
| Vehicle | Years | Shift pattern | Gearbox source | Members |
|---|---|---|---|---|
| Chevrolet and GMC Trucks with the SM420 4-speed Light/medium trucks, buses, military [13] | 1961-1967 | 4 speed, reverse bottom left | Corroborated |
Research notes
Caveats and conflicts (2)
- Stovebolt forum: 4-speed was optional on 1/2 and 3/4 ton trucks (3-speed standard, Warner-sourced HD). Retailer page heading says 1948-1959 but meta says 1947-1959.
- Not confirmed that every 1960 half-ton used it; SM420 was the optional 4-speed.
References
- Retailer. Torque King (retailer) category 1948-1959 GM SM420: SM420 used "from 1948-1959 as the only 4 speed offered for most 1/2 ton to 1 ton models"; Wikipedia Muncie SM420: built 1947 to 1967 for GM pickup trucks. [link]
- Retailer. Torque King (retailer) category 1948-1959 GM SM420: SM420 used "from 1948-1959 as the only 4 speed offered for most 1/2 ton to 1 ton models"; Wikipedia Muncie SM420: built 1947 to 1967 for GM pickup trucks. [link]
- Retailer. Torque King (retailer) category 1948-1959 GM SM420: SM420 used "from 1948-1959 as the only 4 speed offered for most 1/2 ton to 1 ton models"; Wikipedia Muncie SM420: built 1947 to 1967 for GM pickup trucks. [link]
- Retailer. Torque King (retailer) category 1948-1959 GM SM420: SM420 used "from 1948-1959 as the only 4 speed offered for most 1/2 ton to 1 ton models"; Wikipedia Muncie SM420: built 1947 to 1967 for GM pickup trucks. [link]
- Retailer. Torque King (retailer) category 1948-1959 GM SM420: SM420 used "from 1948-1959 as the only 4 speed offered for most 1/2 ton to 1 ton models"; Wikipedia Muncie SM420: built 1947 to 1967 for GM pickup trucks. [link]
- Retailer. Torque King (retailer) category 1948-1959 GM SM420: SM420 used "from 1948-1959 as the only 4 speed offered for most 1/2 ton to 1 ton models"; Wikipedia Muncie SM420: built 1947 to 1967 for GM pickup trucks. [link]
- Retailer. Torque King (retailer) category 1948-1959 GM SM420: SM420 used "from 1948-1959 as the only 4 speed offered for most 1/2 ton to 1 ton models"; Wikipedia Muncie SM420: built 1947 to 1967 for GM pickup trucks. [link]
- Retailer. Torque King (retailer) category 1948-1959 GM SM420: SM420 used "from 1948-1959 as the only 4 speed offered for most 1/2 ton to 1 ton models"; Wikipedia Muncie SM420: built 1947 to 1967 for GM pickup trucks. [link]
- Retailer. Torque King (retailer) category 1948-1959 GM SM420: SM420 used "from 1948-1959 as the only 4 speed offered for most 1/2 ton to 1 ton models"; Wikipedia Muncie SM420: built 1947 to 1967 for GM pickup trucks. [link]
- Wikipedia. Wikipedia Muncie SM420: produced 1947 to 1967 for GM pickup trucks, replaced by the SM465 in 1968; Torque King also lists a 1960-1966 SM420 category. [link]
- Wikipedia. Wikipedia Muncie SM420: 1947-1967 GM trucks; Stovebolt thread on a 1958 Apache names the SM420 as the truck 4-speed. [link]
- Retailer. Torque King (retailer) category 1948-1959 GM SM420: SM420 used "from 1948-1959 as the only 4 speed offered for most 1/2 ton to 1 ton models"; Wikipedia Muncie SM420: built 1947 to 1967 for GM pickup trucks. [link]
- Wikipedia. Wikipedia Muncie SM420: built 1947 to 1967, replaced by the SM465 in 1968; Torque King lists GM part numbers fitting 10 through 30 series 4-speed trucks 1948-1967. [link]
Categories: Gearboxes | GM Muncie
This page was last edited on November 11, 2026. Gearbox codes change by year, engine and market. Send a correction.