Chevrolet S7 headlight bulb sizes include H6024 and H4651 for high beam applications and H6024 and H4656 for low beam applications. The replacement chart covers 1987 to 1988 vehicle 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 1987-1988 Chevrolet S7 uses one of two distinct headlamp configurations: a two-headlamp system or a four-headlamp system, and the required bulb sizes differ between these configurations.
The H6024 is a 7-inch round sealed beam unit operating at 12V and conforming to ANSI standards applicable in the US and Canada. It serves as both the high beam and low beam unit in the two-headlamp configuration, meaning a single sealed beam type handles both functions on that system.
In the four-headlamp configuration, the high beam and low beam positions use different sealed beam types despite sharing the same 4x6-inch rectangular form factor. The H4651 is designated for high beam duty, while the H4656 fills the low beam position.
The H4651 and H4656 are both ANSI-standard 4x6-inch rectangular sealed beam units operating at 12V. Their shared physical form factor means they occupy the same housing size, but they are not interchangeable due to differing beam patterns optimized for high and low beam functions respectively.
All three bulb types used on the Chevrolet S7 are sealed beam units, meaning the lens, reflector, and filament are fused into a single assembly. When a filament fails, the entire unit requires replacement rather than just an internal bulb.
The H6024, H4651, and H4656 all conform to ANSI standards recognized in both the United States and Canada, placing them within a standardized sealed beam classification system that defines their optical output and physical interface.