Buick GS 400 License Plate Bulb Size

The Buick GS 400 license plate light requires a bulb size of 97 for proper installation. Data for the specified component covers the range from 1968 to 1969.

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
1968-1969	97

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. Variant of 1156. 12V, 13W.	97

Other Locations

Additional Notes

The bulb size 97 is an ANSI-standardized type used in both the United States and Canada, operating at 12 volts with a 13-watt output.
The 97 bulb uses a BA15s bayonet base, which is a single-contact base design that seats and locks with a twist-and-push motion.
The 97 bulb carries a single filament, meaning it serves one lighting function rather than combining two functions such as running and brake light duties within one housing.
The Buick GS 400 uses the 97 bulb for the license plate position across the 1968-1969 model years.
The 97 is a variant of the 1156 bulb type. While the two share the BA15s base, they are not identical, and substitution between them without confirming wattage and voltage tolerances may result in fitment or performance issues.