I thought I would post this as an FYI. I looked but didn't see any reference to these bulbs on the forum.
The rear lights on my '57 Chevy were 1157ís which I was quite familiar with.However, the bulbs I took out ofthe front parking/turn signal lights on the í57 (I am pretty sure were neverreplaced); were 1034ís. I had never seen these before. I thought they were somereally obsolete bulb which was replaced by the 1157. Both have dual filamentsand both have identical sockets. Upon doing some research I found the 1034 hasa definite advantage to the 1157 in specific situations. I never knew this.What is key is the secondary filament and using your turn signals.
I found this clear explanation on eHow.
Difference Between 1034 & 1157 Car Bulbs
By David Sandoval, eHow Contributor
Automotive lamps burn out after a long period of use. Often, more than one bulb can serve as a replacement part for nearly any automotive lamp. For example, an 1157 automotive lamp is electrically compatible with a 1034 lamp. However, some notable differences between the two lamps may make one better than the other for your specific situation.
- Primary Filament Operation at 12.8 Volts
- The primary filament is used for normal marker-lamp (the rear light that comes on when you turn on your headlights) operation. The 1157 lamp can sustain 2.10 amps at 12.8 volts, and will last an average of 1,200 hours. The 1034 lamp can handle 1.80 amps at this voltage, and will last an average of 200 hours.
Secondary Filament Operation at 14 Volts
- The secondary filament is used for turn signal operations. The 1157 lamp can sustain 590 milliamps of electrical current at 14 volts, and lasts an average of 3,000 hours. The 1034 lamp lasts an average of 5,000 hours under these conditions.
Considerations When Choosing Which to Install
- Since both lamps are used as combination turn-signal and marker lamps, choose the lamp that suits your needs best. If you do a lot of daytime driving and require a long-lasting signal lamp, install the 1034 lamp. If you do a lot of nighttime driving, and do not need to use your turn signals often, choose the 1157 lamp.