Chevrolet C50 Tail Light Bulb Size

The Chevrolet C50 tail light requires 1157 and 2057 bulb sizes for proper illumination across the various lighting assemblies found on the vehicle. Data for the specific components covers the span from 1960 through 1988.

The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.

Bulb Size by Year Range

Years	Bulb Size
1985-1988	1157
1983-1984	2057
1960-1982	1157

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Dual-filament bulb with BAY15d bayonet base. 12V, 21W/5W.	1157
ANSI standard (US & Canada). Dual-filament bulb with BAY15d bayonet base. Brighter variant of 1157. 12V, 26.9W/8W.	2057

Other Locations

Additional Notes

The 1157 bulb is the dominant tail light specification for the Chevrolet C50, covering the 1960-1981 and 1985-1988 model years, with only a two-year interruption in 1983 and 1984.
The 1157 is a dual-filament bulb operating at 12 volts with a 21W high-filament and 5W low-filament output, mounted on a BAY15d bayonet base, and standardized under ANSI specifications for the US and Canadian markets.
The BAY15d bayonet base features two offset pins that prevent incorrect insertion, a design that ensures consistent seating across compatible sockets.
The 2057 bulb was specified for the C50 in 1983-1984. It shares the same BAY15d bayonet base as the 1157 but operates at higher wattages, rated at 26.9W on the high filament and 8W on the low filament.
Because the 1157 and 2057 share the same BAY15d base, they are physically interchangeable in the socket, though their filament wattages differ, which affects brightness output.
Substituting a 1157 in place of a 2057, or vice versa, will result in a functional fit but will not replicate the original specified light intensity for that model year.
Both bulb types carry ANSI standardization, meaning their electrical and physical characteristics conform to a defined specification rather than varying by manufacturer.
The dual-filament design of both bulb types serves the combined tail light and brake light function within a single housing, with each filament activating independently depending on the circuit engaged.