RC-15 radiator caps?

[Pacecarjeff]

Does anyone know the exact application, or year for these 3 different "big ear" RC15 cap designs?

Picture is the 3 styles, and what I guessed to be their applications.
2 circles flat rivet. (1968L - 1972)
2 circles hollow rivet. (1966 - 1968)
No circles hollow rivet. (1964 - 1966E)

Does anyone know the true story?

[Verne_Frantz]

Jeff,
I believe the one with the smaller recess and hollow rivit goes back even earlier. '62 & '63 big cars with A/C used that 15# cap. I wouldn't know for sure about the Corvettes, but I'd assume they'd used the same ones.

Verne

[mrrec]

I generally agree with the dates as discussed. Be careful about the repros, though. There are the cheapo repros that can be spotted a mile away, but there are also some very good caps that are only lacking in some tiny details (like the length of the arrow). None of the repros are right on the sealing side so that is a good way of differentiating on eBay.
Dave

[Tim Penton]

Dave, Did you get my email? T