Ford Gran Torino front turn signal bulbs utilize 1034NA or 1157NA sizes, while rear turn signal bulbs use 1157 size. The replacement chart covers 1972 through 1976 production 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 Ford Gran Torino front turn signal uses two distinct bulb types across its 1972-1976 model years: the 1034NA for 1972 and 1975-1976, and the 1157NA for 1973-1974.
The rear turn signal position uses the 1157 bulb consistently across all five model years covered, from 1972-1976.
All three bulb types specified for the Gran Torino, the 1034NA, 1157NA, and 1157, share the BAY15d bayonet base, a double-contact offset-pin base design that physically locks the bulb into position with a twist.
All three bulb types operate at 12 volts and carry a dual-filament rating of 21W/5W, where the higher wattage filament serves the turn signal function and the lower wattage filament serves a secondary function such as parking or running light.
The 1034NA is described as a variant of the 1157, meaning the two share the same base type and electrical ratings but differ in glass coloring, with the 1034NA featuring natural amber glass rather than clear glass.
The 1157NA similarly carries natural amber glass, distinguishing it from the clear-glass 1157 used in the rear position. Both the 1034NA and 1157NA produce an amber output directly from the glass rather than relying on an amber lens in the housing.
Because the 1034NA and 1157NA share the BAY15d base and identical 12V/21W/5W ratings with the standard 1157, they are electrically interchangeable, though substituting a clear 1157 for an NA-suffix bulb would alter the color output at the lens.
All three bulb types conform to ANSI standards recognized in both the United States and Canada, indicating they meet a defined set of dimensional and photometric requirements for North American automotive applications.