International C1300 front side marker bulbs use 194 size while rear side marker bulbs use 97 size. The replacement chart covers 1963 to 1964 production 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 International C1300 uses two distinct bulb types across its front and rear side marker positions for the 1963-1964 model years: the 194 at the front and the 97 at the rear.
The 194 is an ANSI-standard miniature wedge bulb in the T10 form factor, rated at 12V and 3.78W, and is classified for Light Duty applications on the C1300.
The T10 wedge base of the 194 requires no locking mechanism for retention, as the wedge shape itself holds the bulb within the socket.
The 97 is an ANSI-standard single-filament bulb rated at 12V and 13W, fitted with a BA15s bayonet base, and serves the rear side marker position on the C1300 across both listed model years.
The BA15s designation indicates a single-contact bayonet base with a 15mm collar, which is a non-indexing base type, meaning the bulb can be inserted in any rotational orientation.
The 97 is described as a variant of the 1156 bulb. Despite this relationship, the two are not directly interchangeable, as differences in wattage and base contact configuration exist between variants in this family.
The power differential between the two bulb types is substantial: the rear 97 draws approximately 3.4 times more wattage than the front 194, reflecting the greater luminous output typically required for rear marker visibility.
Both the 194 and 97 conform to ANSI standards recognized in both the United States and Canada, indicating standardized dimensional and electrical tolerances across North American markets.