Responding to somebody elses PM.
You can put your questions into the thread so all can hear. We aren't hijacking.
I have no idea why it had any numbers stamped on it. But it did. They were very neat so it appeared that they were stamped simultaneously with a long die.
Some people used to see the 7K27 number and think it was a K code.
The J code got rebuilt with a 68 302 block and sold.
NO, J code heads are NOT hipo heads. Just plain old renumbered 289 C/A code heads with the same peanut shaped chambers. They are identical in every way
to the C60E except the casting numbers. Same 124 cc ports, valves, 53.5 cc chambers.
What made the J heads get numbered 4V is that Ford also made a large chamber 289 and a large chamber 302 head in 68. So they distinguished the small chamber 4V head with 302 4V under the valve covers, and also casting numbers under the intake.
Early 351W heads through 74 with the big spark plugs have 60 cc chambers and 144 cc intake ports with 1.84 valves.