68 Dart damaged instrument cluster circuit board
www.mymopar.com may have the '68 Dodge FSM. I have the Plymouth version in paper and its 158 for illumination and turn signal indicators for Valiants.
According to this Wagner's 2008 catalog, they are equally bright, but they 158 draws less power.
The 194 has a longer lamp life, but that 500 hours is a lot of turn signal blinking! and even for instrument illumination, its a lot of years. More if you don't always have the instruments on maximum brightness.
edit.
Another differenec is the filiment type.
I don't specialize in lighting, but the c-2V shape sure looks like it follows the bulb shape and will be more evenly dispersed to the sides, and less out toward our eyes.
Owners book is often better for lamps anyway.
www.mymopar.com may have the '68 Dodge FSM. I have the Plymouth version in paper and its 158 for illumination and turn signal indicators for Valiants.
Answer
The aftermarket would much prefer you buy one size fits most, works just the same for us, performing as intended not our concern, why do you care it an old car, and this way we only have to stock one part....
According to this Wagner's 2008 catalog, they are equally bright, but they 158 draws less power.
The 194 has a longer lamp life, but that 500 hours is a lot of turn signal blinking! and even for instrument illumination, its a lot of years. More if you don't always have the instruments on maximum brightness.
edit.
Another differenec is the filiment type.
I don't specialize in lighting, but the c-2V shape sure looks like it follows the bulb shape and will be more evenly dispersed to the sides, and less out toward our eyes.