Chevrolet P40 Headlight Bulb Size

Additional Notes

• The Chevrolet P40 headlight specifications across 1979-1988 are exclusively for 4-headlamp configurations, meaning all listed bulb sizes apply only to vehicles equipped with that arrangement.
• The H6024 is a 7-inch round sealed beam unit rated at 12V and conforming to ANSI standards for the US and Canadian markets. It serves as both a high beam and low beam option across most of the listed model years.
• The H4651 and H4656 are both 4x6-inch rectangular sealed beam units rated at 12V under the same ANSI standard. The H4651 is designated for high beam duty, while the H4656 fills the low beam role, making the two non-interchangeable despite sharing the same physical form factor.
• The H6054 is a 5x7-inch rectangular sealed beam unit, also rated at 12V and ANSI-compliant. It appears exclusively in the 1984 model year for both high beam and low beam positions, distinguishing that year from the rest of the range.
• All four bulb types are sealed beam units, meaning the lens, reflector, and filament are fused into a single assembly. Replacement requires swapping the entire unit rather than an internal bulb.
• The H6024 round sealed beam and the rectangular sealed beam options represent two distinct headlamp system designs. Within a 4-headlamp setup, these two types are not interchangeable with each other due to differing shapes and mounting requirements.