My 1968 series 1 1/2 coupe has a cylinder head with number DJ823 on the top of the rear of the head. Can someone please tell me details about my head. I can not see any other numbers!

 

Around the time that the XK engine went from the smooth polished cam covers to the ribbed style, Jaguar stopped stamping the engine serial numbers on the cylinder head. The DJ823 number that you see is the casting number for the head. Someone may have tabulations of the casting numbers, but I have not been able to find such data.