[MustangIICobra]

hello again. just trying to find out more about the motor that is in my 1977 mustang II. Obviously its not original since it came with the 302 but now it has a 289 and the number stamped inside of the valve cover is 5J20 can anyone help me with what this identifies??

 

[hydroflame]

the only way to get the casting number from the head is to pull the head its on the bottom the casting number your looking at is the valve cover only which is meaningless in finding the origins of the motor case in point mine has a 75 torino 302 block and 65 289 hipo heads if i rember right i done this in 87 and i'm asking my painter father for help remebering so i'll find out for real this winter when i do my tear down and run the casting numbers.