GMC 100 front and rear turn signal bulbs utilize 3 distinct sizes including 1034, 1073, and 1129, with the front position accommodating all 3 sizes and the rear position using 1073 or 1129 bulb configurations. The replacement chart covers 1951 through 1959 model years with corresponding bulb size specifications for each production year.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.