Chevrolet Bel Air Tail Light Bulb Size

The Chevrolet Bel Air tail light utilizes bulb sizes 1157, 1034, and 1154 depending on the specific production period for the vehicle. Provided information covers the range from 1950 through 1975 for the specified automotive lighting components.

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
1964-1975	1157
1955-1963	1034
1950-1954	1154

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. Variant of 1157. 12V, 21/5W.	1034
ANSI standard (US & Canada). Dual-filament bulb with BAY15d bayonet base. Older variant of 1157. 6V/12V.	1154

Other Locations

Additional Notes

The 1157 bulb is the tail light specification for the Chevrolet Bel Air across the 1964-1975 model years, making it the most widely used bulb type in these specifications by a considerable margin.
The 1157 operates at 12V with a dual-filament configuration rated at 21W and 5W, where the higher wattage filament serves the brake or turn signal function and the lower wattage filament serves the running light function.
The 1034 bulb is specified for the 1955-1963 model years and shares the same BAY15d bayonet base and 12V, 21W/5W electrical ratings as the 1157, as it is a variant of that type.
Despite their shared base type and voltage ratings, the 1034 and 1157 are distinct ANSI-designated bulbs, and their interchangeability should not be assumed without verification against fitment requirements.
The 1154 bulb is specified for the 1950-1954 model years and is described as an older variant of the 1157, retaining the BAY15d bayonet base but carrying a dual voltage rating of 6V/12V rather than a fixed 12V specification.
All three bulb types across these specifications share the BAY15d bayonet base, a double-contact offset-pin base design used to prevent incorrect single-filament bulb installation in dual-filament sockets.
The 6V/12V rating of the 1154 reflects the transitional period in automotive electrical systems, during which manufacturers moved from 6-volt to 12-volt charging systems.
All three bulb types carry ANSI standardization applicable to the United States and Canada, meaning their specifications conform to a defined industry standard rather than a proprietary designation.