[cosworthfreak]

That J number on the strut tower appears to be ‘JF’ but I think it’s actually JE. The original compliance plate would have had the J number stamped on it as well. Either JE or JF points to a GT V6, as does the CK17 beginning to the chassis number. If it was JF it would be originally an auto car, but as there were no autos made in June 1970 (weren’t built at all until August 1970), I’m thinking it is JE which matches with the letter from Ford.

The ‘69 and most ‘70 cars had a dual numbering system like the Falcons had. The CK number is the body number, and the J number is the engine number (although also stamped on the driver’s side shock tower).

I don’t have your car in my records but I have some before and after your CK body number. The JE number on yours is between them, so seems to align (although without the compliance plate I can’t be definitive).