GMC W6500 Forward Headlight Bulb Size

The GMC W6500 Forward headlight bulb sizes include H5001, H6054, and H6024 for high beam applications and H5006, H6054, and H6024 for low beam applications, with each bulb size corresponding to specific vehicle configurations. The replacement chart covers 1987 through 1996 model years and documents the headlight bulb specifications across the production range.

The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.

High Beam Headlight

Years	Bulb Size
1996	H5001 (Tiltmaster)
1992-1995	H5001 (Tiltmaster)
	H6054 (With 2 Rectangular Headlamps)
	H6024 (With 2 Round Headlamps)
	H4651 (With 4 Rectangular Headlamps)
1989-1991	H5001 (Tiltmaster)
	H6054 (With 2 Rectangular Headlamps)
	H4651 (With 4 Rectangular Headlamps)
1988	H5001 (Tiltmaster)
	H6054 (With 2 Rectangular Headlamps)
	H6024 (With 2 Round Headlamps)
	H4651 (With 4 Rectangular Headlamps)
1987	H5001
	H6054 (With 2 Rectangular Headlamps)
	H6024 (With 2 Round Headlamps)
	H4651 (With 4 Rectangular Headlamps)

Low Beam Headlight

Years	Bulb Size
1996	H5006 (Tiltmaster)
1992-1995	H5006 (Tiltmaster)
	H6054 (With 2 Rectangular Headlamps)
	H6024 (With 2 Round Headlamps)
	H4656 (With 4 Rectangular Headlamps)
1989-1991	H5006 (Tiltmaster)
	H6054 (With 2 Rectangular Headlamps)
	H4656 (With 4 Rectangular Headlamps)
1988	H5006 (Tiltmaster)
	H6054 (With 2 Rectangular Headlamps)
	H6024 (With 2 Round Headlamps)
	H4656 (With 4 Rectangular Headlamps)
1987	H5006
	H6054 (With 2 Rectangular Headlamps)
	H6024 (With 2 Round Headlamps)
	H4656 (With 4 Rectangular Headlamps)

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). 4-inch square sealed beam unit. Not a replaceable bulb — the entire unit is replaced. 12V.	H5001
ANSI standard (US & Canada). 5x7-inch rectangular sealed beam unit. Not a replaceable bulb — the entire unit is replaced. 12V.	H6054
ANSI standard (US & Canada). 7-inch round sealed beam unit. Not a replaceable bulb — the entire unit is replaced. 12V.	H6024
ANSI standard (US & Canada). 4x6-inch rectangular sealed beam unit. Not a replaceable bulb — the entire unit is replaced. 12V.	H4651
ANSI standard (US & Canada). 5.75-inch round sealed beam unit. Not a replaceable bulb — the entire unit is replaced. 12V.	H5006
ANSI standard (US & Canada). 4x6-inch rectangular sealed beam unit. Not a replaceable bulb — the entire unit is replaced. 12V.	H4656

Other Locations

Additional Notes

The GMC W6500 Forward uses six distinct sealed beam bulb types across its headlight specifications: H5001, H5006, H6024, H6054, H4651, and H4656. All six conform to ANSI standards recognized in both the United States and Canada and operate on 12V electrical systems.
Every bulb type listed for the W6500 Forward is a sealed beam unit, meaning the lens, reflector, and filament are fused into a single assembly. When a filament fails, the entire unit requires replacement rather than an internal bulb swap.
The H6054 and H6024 are the most broadly specified bulb types across the W6500 Forward's headlight configurations. The H6054 is a 5x7-inch rectangular sealed beam used for high and low beam in two-rectangular-headlamp configurations, while the H6024 is a 7-inch round sealed beam serving the same dual role in two-round-headlamp configurations.
The Tiltmaster variant of the GMC W6500 Forward uses a separate pair of sealed beam types exclusive to that configuration: the H5001, a 4-inch square unit for high beam, and the H5006, a 5.75-inch round unit for low beam. These two types do not appear in any other headlamp configuration listed in the specifications.
Vehicles equipped with four rectangular headlamps use the H4651 for high beam and the H4656 for low beam. Both are 4x6-inch rectangular sealed beam units, making them physically identical in size despite serving different beam functions. Substituting one for the other would result in incorrect beam output.
The H6054 sealed beam is the only type that functions as both a high beam and a low beam unit within the same configuration. In two-rectangular-headlamp setups, it covers both roles, which is a characteristic of certain sealed beam systems where a single lamp type handles dual-beam output.
The H6024 round sealed beam is specified for 1987-1988 and 1992-1995 model years, but not for 1989-1991 or 1996. This reflects configuration-level fitment variation rather than a universal round-headlamp option across all years.
Because the H4651 and H4656 share the same 4x6-inch physical format, correct installation depends on matching the beam designation rather than the physical size of the unit. Misidentification between these two types is a known fitment risk in four-headlamp rectangular configurations.