1967 GT350 scoop red side markers

No definitive answer on the lights. When the 67's were introduced the GT40's and other Ford race machines used a white light to illuminate the numbers on the sides of the cars. That similarity most likely inspired the scoop light design even though the lens were red instead of clear. They were wired both as running lights as well as turn signal/brake lights depending on the car, the day and which way the planets were aligned . This theory has been the most widely accepted for the past 25 +years and seems to be the most plausibly until something better one comes along.

 

Yep, Bob and I debated the way they were wired a few years back here on this forum. The conclusion was they must have been wired either way. There were reports one way (like yours) and the other way (a couple of original owners, plus Shelby literature stating "eye level" brake and turn signals) so, as Bob mentioned, must have been something to do with the way the planets alined in the age of Aquarius.

And, these lights might be a little too high to be on a door to light up the numbers at night, but, Dietz, the maker, might have had other styles.