Chevrolet Biscayne Tail Light Bulb Size

The Chevrolet Biscayne tail light utilizes 1157 and 1034 bulb sizes depending on the specific production period for the vehicle. Available data covers the range from 1958 to 1972.

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
1964-1972	1157
1958-1963	1034

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

Other Locations

Additional Notes

The Chevrolet Biscayne tail light specifications cover model years 1958-1972, with two distinct bulb types used across that span: the 1034 and the 1157.
The 1034 bulb was specified for the 1958-1963 model years, while the 1157 replaced it for the 1964-1972 model years.
Both the 1034 and 1157 are ANSI-standardized dual-filament bulbs rated at 12V with a 21W/5W output, where the higher wattage filament serves the brake and turn signal functions and the lower wattage filament serves the running light function.
Both bulb types share the BAY15d bayonet base, a two-pin offset base design that physically locks the bulb into the socket and prevents incorrect insertion.
Although the 1034 is described as a variant of the 1157, the two are not confirmed as interchangeable within these specifications, and substituting one for the other without verification of socket and housing compatibility carries fitment risk.
The shared BAY15d base between the 1034 and 1157 means the two bulbs may physically seat in the same socket, but electrical or optical differences between variants can affect performance in applications where only one type is specified.
Both bulb types carry ANSI standardization applicable to the United States and Canada, meaning their electrical and physical characteristics conform to a defined industry specification rather than a proprietary standard.