I have pictures on my phone but don't know to send them I will see what I can do thanks.

Ah!  this is weird. In some cases references to numbers, for instance for 1957 heads, should read "letters" such as ECZ-G..  
And there are no 1970s Y-Blocks...


Paul

The "Tag" is the date code.  That code is usually in the format year, month, day.  The letters and numbers you posted don't make sense, though.

Can you post pictures of all the locations these numbers should be, as well as the date codes?

There were no Ford aftermarket HP heads.


Lawrenceville, GA

The heads have been blasted and I see no other numbers anywhere  The 60 A and the C69 are under the headers They almost look like they are on a tag and screwed into the head but I can not unscrew or pry the off. the heads are on a supercharged race motor from the 70s did Ford make any HP aftermarket heads? 
  

My 57 G heads have the G on the mating surface and under the water port. Not sure if they all had it.

Are these cylinder heads still on an engine? Do the heads have freeze plugs in their ends?  The head casting numbers on some of the earlier castings will be on the exhaust side of the heads which makes the casting numbers somewhat invisible until the exhaust manifolds are removed.  As shown in the supplied links, many of the later model heads have the casting numbers either under the valve cover or under the water ports where the intake bolts on.  I have come across instances where the casting numbers under the water ports have been ground off smooth by persons unknown.

Lorena, Texas (South of Waco)

The numbers are in one of those two spots.  50 years of baked on grim may not come off with a sandblaster.  Get a pick or sacrificial screwdriver and make sure it is absolutely clean.  The only other option is that someone ground the numbers off but there would be clear evidence of that.


Lawrenceville, GA

yes

have you looked under the front water port infront of the intake side of heads?


  AussieBill            YYYY    Forever Y Block     YYYY

 Down Under, Australia

Heads are disassembled and sandblasted  these are the only numbers makes no sense but it must be a Henery thing.