[ERA427]

I have a 428FE in my ERA Cobra. I bought the car used with this engine. It has the C6... block. And it has 1968CJ heads (C8...).

The car was sold as having a 1966 428 Cobra Jet. But I later discovered that the Cobra Jet wasn't offered until 1968.

I tracked down the guy who rebuilt the engine before it was put in the car. He got it from a low mileage car that had been crashed but he couldn't recall what kind. Regardless, he said the heads were already on it and he thought it was a real cobra jet because it had the CJ heads. He added a 1966 PI intake so it is a visual clone of 1966 Shelby.

Does anyone know if a 1968 Cobra Jet motor would/could have been sold new from Ford with a 1966 block?

(I've searched everywhere I can find on the internet for this answer but nothing is conclusive).

Are there any other easy ways to tell the difference of a stock and CJ (without taking things apart)?