GMC Sprint headlight bulbs utilize H4651 and H6024 sizes for high beam applications, with H4652 and H6024 sizes serving low beam functions in this model. The replacement chart covers vehicle production years spanning 1971 to 1977, detailing bulb size specifications across the model's manufacturing period.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The GMC Sprint uses two sealed beam form factors across its model years: the H6024, a 7-inch round unit, and the H4651/H4652 pair, which are 4x6-inch rectangular units. All three types operate at 12V and conform to ANSI standards recognized in both the United States and Canada.
Sealed beam units are self-contained assemblies in which the filament, reflector, and lens are fused into a single housing. When a sealed beam fails, the entire unit is replaced rather than an internal bulb.
The GMC Sprint used the H6024 for both high beam and low beam positions from 1971-1975. Because the same part number serves both functions in those years, the H6024 is a dual-purpose unit capable of operating in either headlight position.
For the 1976-1977 model years, the Sprint transitioned to rectangular sealed beams, with the H4651 assigned to the high beam position and the H4652 assigned to the low beam position. These two part numbers are distinct variants of the same 4x6-inch rectangular form factor and are not interchangeable with each other despite their physical similarity.
The H6024 round sealed beam and the H4651/H4652 rectangular units are not interchangeable, as they differ in both shape and mounting configuration. Installing a unit from the wrong form factor group would require modification to the headlight housing.
The H4651 and H4652 share the same 4x6-inch rectangular sealed beam housing but carry separate ANSI designations, reflecting differences in their internal filament configuration that produce distinct beam patterns for high and low beam functions.