Chevrolet Chevelle front side marker bulbs utilize 194 or 194NA bulb sizes, while rear side marker bulbs use 194 size specifications. The replacement chart covers 1968 through 1973 production years with corresponding bulb size data.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 194 bulb is an ANSI-standard miniature wedge type with a T10 form factor, rated at 12 volts and 3.78 watts, recognized under both US and Canadian standards.
The 194NA shares the same T10 wedge form factor, voltage, and wattage as the 194 but is distinguished by natural amber-tinted glass, which produces a colored output without a separate lens filter.
The Chevrolet Chevelle uses the 194 bulb across both front and rear side marker positions for the 1969-1973 model years, with the rear side marker position using the 194 exclusively across all six listed model years.
The front side marker positions for the 1968 and 1971 Chevelle specify the 194NA rather than the clear 194, meaning those positions required a factory amber bulb rather than a clear one.
Because the 194 and 194NA share the same T10 wedge base and electrical ratings, they are physically interchangeable, though substituting a clear 194 in a position specified for the 194NA would alter the color output of that marker light.
The T10 wedge base design requires no retaining clip or bayonet twist for installation, as the wedge-shaped base is held in place by the socket housing itself.
At 3.78 watts on a 12-volt circuit, the 194 and 194NA each draw approximately 0.315 amperes, which is consistent with low-current marker light applications.