GMC K25 Tail Light Bulb Size
The GMC K25 tail light requires 2 distinct bulb sizes: 198 and 1034, with each size serving specific functions in the rear lighting assembly. The replacement chart covers vehicle production spanning from 1967 through 1978, detailing bulb specifications across all model years within that range.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
Bulb Size by Year Range
| Years | Bulb Size |
|---|---|
| 1969-1978 | 198 |
| 1967-1968 | 1034 |
Bulb Specifications
| Description | Bulb Size |
|---|---|
| ANSI standard (US & Canada). Miniature wedge bulb (T5). 12V, 2W. | 198 |
| ANSI standard (US & Canada). Dual-filament bulb with BAY15d bayonet base. Variant of 1157. 12V, 21/5W. | 1034 |