International SA122 front side marker bulbs measure 194 in size, while rear side marker bulbs measure 97, with each bulb type specified for its corresponding location. The replacement chart covers 1956 to 1957 vehicle production years and contains 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 SA122 uses the 194 bulb for the front side marker position across the 1956-1957 model years, under the Light Duty classification.
The 194 is a T10 miniature wedge bulb rated at 12V and 3.78W, conforming to ANSI standards recognized in both the United States and Canada.
The wedge base of the 194 requires no metal base or locking pins, as the glass envelope itself acts as the retention mechanism within the socket.
The rear side marker position on the 1956-1957 International SA122 (Light Duty) uses the 97 bulb, a higher-wattage single-filament type compared to the front position.
The 97 bulb uses a BA15s bayonet base, a single-contact fitting where the bulb is inserted and rotated to lock into place.
At 13W, the 97 draws considerably more power than the 3.78W front marker bulb, reflecting the greater light output typically associated with rear marker and signal functions.
The 97 is described as a variant of the 1156, meaning the two share a similar single-filament, single-contact bayonet configuration, though they are not the same part and are not listed as interchangeable in these specifications.
Both the 194 and 97 are rated at 12V, consistent with the standard automotive electrical systems of the mid-1950s era.
The front and rear side marker positions on the SA122 use physically incompatible base types, the wedge base of the 194 versus the BA15s bayonet base of the 97, making cross-position substitution impossible without socket modification.