When doing replacement or upgrading on 1965 – 1967 Buick Gran Sport, the bulb size guide is necessary for you to take the reference.
Jump to corresponding car model with the catalog bellow.

Low Beam Headlight 1965 – 1967 H5006
High Beam Headlight 1965 – 1967 H5001
Back Up Light 1965 – 1967 1156
Brake 1965 – 1967 1157
Dome Light 1965 – 1967 211-2
Front Turn Signal 1965 – 1967 1157
License Plate 1965 – 1967 97
Parking Light 1965 – 1967 1157
Rear Turn Signal 1965 – 1967 1157
Tail Light 1965 – 1967 1157
Courtesy 1965 – 1967 90
Engine Compartment Light 1965 – 1967 89
Glove Box 1965 – 1967 1893
Map Light 1965 – 1967 89
Trunk 1965 – 1967 89