the cast numbers on my block are
2K18 (date ?)
Yes, the date.
Engine block engineering number. Correct for the original build on this car.
stamped 01527 (I've lost the tag with engine number to verify)
This is the date the engine was assembled.Are you sure it isn't 01572? (January 5, 1972)
on the front inside corner of the heads is a "4"
The engineering ID for the 4v heads.
under the valve cover I only found
2J2 (date ?)
The casting date of the heads. It's rare to find them both exactly the same date.
circle with L5316
Escapes me at the moment
large C with F in center
The "mint mark" of the Ford Cleveland Foundry (casting facility)
would the head cast number be under the intake?
Yes. It is under one of the intake runners. You have to remove the head to see it. If the intake manifold is off you should be able to see it with a mirror.