CK13 is not a legitimate Ford code, the closest being CK14, which is a Capri Deluxe, 1600 1V engine. The Mk.1 Capri V6 GT was a code CK17, from 1970 to 1972. The Ford 'Essex' V6 was only ever used in the Mk.1 Capri here in Australia. One was however transplanted into a Mk.1 Escort by Ford Australia and still lives on in Maffra, Victoria!