These heads are on a 318 block with 360 rotating assembly.One head has the folowing numbers under the valve cover: 5300 and 6671, also L8 and HN.
The other head: 5302 and 0466 also a circled 22 by 0466.
Outside valve cover by spark plug holes: 104 and FG on one head and looks like 8185 and FS.
Thanks for any help, I am looking for valve size, combustion chamber cc and original application. -- Chuck