Chevrolet Bel Air front side marker bulbs utilize 194 or 194NA bulb sizes, while rear side marker applications require 194 size bulbs. The replacement chart covers 1968 through 1975 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 Chevrolet Bel Air uses the 194 bulb as the sole bulb type across both front and rear side marker positions for all listed model years from 1968 to 1975, with the exception of certain front side marker positions that call for the 194NA variant.
The 194 is an ANSI-standardized miniature wedge bulb in the T10 form factor, rated at 12 volts and 3.78 watts. The T10 designation refers to a tubular envelope that is 10/8 of an inch wide, fitted with a wedge-style base that requires no separate socket locking mechanism.
The 194NA shares the same ANSI classification, form factor, voltage, and wattage as the standard 194, but its glass envelope is tinted natural amber rather than clear.
Both the 194 and 194NA carry ANSI recognition for use in the United States and Canada, meaning both conform to the same dimensional and electrical standards within those markets.
The front side marker position on the Chevrolet Bel Air specifies the 194NA for the 1968, 1971, and 1974 model years, while the remaining front side marker years from 1969-1970 and 1972-1973 and 1975 specify the clear 194.
The rear side marker position specifies the standard 194 bulb without exception across all listed model years from 1968 to 1975.
Because the 194NA produces amber-colored light through its tinted glass rather than through an amber-colored lens, substituting a clear 194 in a position specified for the 194NA would alter the color output of that marker light.
Despite the color difference between the two variants, the identical T10 wedge base and electrical ratings of the 194 and 194NA mean both physically fit the same socket type.