GMC P152 front and rear side marker bulbs utilize a 63 size across both positions. The replacement chart covers 1950 to 1951 model years with corresponding bulb specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The GMC P152 uses the type 63 bulb for both front and rear side marker positions across the 1950-1951 model years.
The type 63 is an ANSI-standardized bulb recognized in both the United States and Canada, meaning it conforms to a shared North American specification rather than a regional or proprietary standard.
The type 63 operates on a 12-volt electrical system, which aligns with the standard automotive DC voltage used in conventional vehicle electrical architectures.
At 0.63 watts, the type 63 is a very low-wattage bulb, consistent with its role as a passive visibility marker rather than a primary lighting source.
The type 63 uses a BA9s base, which is a miniature bayonet fitting with a 9mm cap body. This base type requires a quarter-turn insertion and is not interchangeable with screw-base or wedge-base sockets.
The single-filament construction of the type 63 means it serves only one lighting function per bulb, with no provision for dual-intensity operation such as combined marker and turn signal use.
The front and rear side marker positions on the GMC P152 share the same bulb type for both model years covered, indicating a uniform socket specification across all four marker locations on the vehicle.