When doing replacement or upgrading on 1964 – 1973 Chevrolet Chevelle, the bulb size guide is necessary for you to take the reference.
Jump to corresponding car model with the catalog bellow.

Low Beam Headlight1964 – 1970 H5006
High Beam Headlight1964 – 1970 H5001
High Beam and Low Beam Headlight1971 – 1973 H6024
Back Up Light1964 – 1973 1156
Brake1964 – 1973 1157
Dome Light1964 – 1965, 1967 – 1971 211-2
1972 – 1973 578
1966 631
Front Side Marker1969 – 1970, 1972 – 1973 194
1968, 1971 194NA
Front Turn Signal1964 – 1973 1157
License Plate1966 – 1967 1155
1964 – 1965, 1968 – 1971 67
1972 – 1973 97
Parking Light1964 – 1973 1157
Rear Side Marker1968 – 1973 194
Rear Turn Signal1964 – 1973 1157
Tail Light1964 – 1973 1157
Courtesy1972 1816
1966 211-2
1973 212-2
1964 – 1965, 1967 – 1971 631
Engine Compartment Light1972 – 1973 1003
1964 – 1970 1156
Glove Box1972 1893
1964 – 1971, 1973 1895
Map Light1964 – 1968, 1971 562
Radio Display1972 – 1973 1816
1964 – 1971 1893
Trunk1964 – 1973 1003