I've been going through the 67 Shelby section with more zeal of late and ran into this thread.
Some good research has been done on GE bulbs -- one of the most common Ford bulbs -- here:
http://www.chrysler300club.com/tech/headlamp/lamp1.htmlCredit for this information should go to the Chrysler 300 club.
Of course they don't get into Ford script bulbs but I thought some of the GE identifying marks were important. Note that the GE bulbs in question here were during the early Mustang production time -- not before.
- Prior to January 3, 1972 all Ford/GE bulbs were wide flute lens design
- January 3, 1972 and on had the narrow or small flute design
- Prior to January 3, 1972 the top of the bulb had a "1" for the 5¾ inch high beam lamp, "2" for the 5¾ inch low/high beam lamp
- January 3, 1972 and on had "1C1" for the 5¾ inch high beam lamp, "2C1" for the 5¾ inch low/high beam lamp
I understand judges look for GE bulbs (and Tung Sol?) at minimum and Ford script (optional?) but do they also look for correct flutes and top of bulb markings?
I've been collecting bulbs and find that non-Ford vendors often give old bulbs away!