International C1100 front side marker bulbs measure 194 in size, while rear side marker bulbs measure 97 in size. The replacement chart covers 1963 to 1964 model years with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The International C1100 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 classified under the T10 form factor, operating at 12V and drawing 3.78W, which places it in the low-wattage range typical of marker and courtesy lighting applications.
The T10 wedge base of the 194 requires no locking mechanism for retention; the bulb is held in place by the socket walls alone, a design common in compact marker light housings.
The 97 is an ANSI-standard single-filament bulb fitted with a BA15s bayonet base, operating at 12V and drawing 13W, a significantly higher wattage than the front marker bulb.
The BA15s designation on the 97 indicates a single-contact bayonet base with a 15mm collar, which is not interchangeable with the BA15d double-contact variant used in some other automotive applications.
The 97 is noted as a variant of the 1156, meaning the two share the BA15s base type, though the 97 draws less wattage than the standard 1156 rated at approximately 26.9W, making direct substitution a consideration that depends on socket and housing compatibility.
Both the 194 and 97 conform to ANSI standards recognized in the United States and Canada, indicating standardized dimensional and electrical tolerances within those markets.
The Light Duty classification applied to both the 1963-1964 C1100 entries reflects a vehicle weight or usage rating rather than a bulb specification, and it governs which bulb sizes are listed as applicable for that configuration.