Technical Ford flattie heads help

Excuse my ignorance on the ford flathead, have worked on many chevy 235s and 216s but this is my first flathead I have a motor with stock EAB heads but found these aluminum heads, they say made in USA and have FOG on them as well I have searched the internet with no luck on these particular heads i have been a member on the hamb for awhile so I figured there are some gurus on here that could school me. thanks in advance any help is appreciated

 

Those are early 21 stud.Is your engine 21 or 24 stud?

 

EAB heads would be 24 stud.

 

My engine is a 24 stud so they wont work, so these are factory aluminum heads?

 

The FOG heads are a non Ford replacement head carried by many parts stores back in the day.

 

42Merc thanks, are these any good for performance, any issues with them?

 

Pretty sure they are stock replacement heads with low compression. If for the late domed pistons, circa 79CC for checking purposes.
For future reference...look at the bottom row of holes on your 24 stud EAB's and the bottom row of the 21 stud heads shown, and you will be able to instantly tell a 21 from a 24 without even counting.

 

Thanks everyone