When upgrading the stock halogen / incandescent lamps to led lighting bulbs, the bulb size guide will be much helpful, below are the bulb size guide for 2004~2005 Chevrolet Classic; yet it is for reference only, it is suggested to check the owner manual to confirm the bulb size guide is correct before purchasing.
- High beam headlight: 9005; Low beam headlight: 9006
- Front turn signal light ( blinker light)/ Parking light: 3157 / 3157-SCK / 3157NAK / 3157A
- Rear turn signal light: 3156 / 3156K
- Brake light / Tail light: 3057 / 3057K / 3157-SCK
- Back-up reverse light: 3057 / 3157-SCK
- License plate light / Tag light: 194
- Interior Dome light : 561
- Interior Map light: 211-2
- Interior Trunk / Cargo area light: 211-2
- Front & rear side marker light : 194 / 194NA / 24
- Glove box light: 194
- 3rd Brake light / Center high mount stop light: 912
- Vanity Mirror Light: 37
- Ash tray light: 161
- Courtesy light: 168
