The only entries I could find in the 75 Ford Car Parts are that is it's used on: 1965 Thunderbird 390; 1965-67 Ford 427; and 1966 Thunderbird 428, all with transistor ignitions (there may be Mercury applications). That info has contradictions, the replacement is as indicated above, the original listing only states the 66 T-Bird came with that cap.
Rare - yes. Desirable - only on a T-Bird forum.
Jim
