Chevrolet Biscayne front and rear turn signal bulbs utilize 1157 and 1034 size specifications across the vehicle's production run. The replacement chart covers 1958 through 1972 model years with corresponding bulb size data.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Chevrolet Biscayne uses two distinct turn signal bulb types across its production run: the 1034 for 1958-1963 models and the 1157 for 1964-1972 models. This split applies equally to both the front and rear turn signal positions.
The 1157 bulb is an ANSI-standardized dual-filament type operating at 12 volts with a 21W/5W filament rating. The higher 21W filament serves the active turn signal function, while the 5W filament handles the lower-intensity parking or running light function.
The 1034 bulb shares the same dual-filament 12V, 21W/5W configuration as the 1157 and is classified as a variant of it under the ANSI standard. Both types use the BAY15d bayonet base, which features two offset pins to ensure correct orientation during installation.
Although the 1034 and 1157 share the BAY15d base type and identical voltage and wattage ratings, they are distinct part numbers under the ANSI standard. The variant relationship between them does not confirm direct interchangeability without further verification against socket and housing fitment for the specific model year.
Both the 1034 and 1157 carry ANSI standardization applicable to the US and Canadian markets, meaning replacements sourced within those markets are expected to conform to the same electrical and base specifications.
The front and rear turn signal positions on the Biscayne use the same bulb size for any given model year, so the 1034-to-1157 transition at the 1964 model year affected all four turn signal positions simultaneously.