When you say "Mannel's manuals" (plural) are you referring to the Ford assembly manuals?
Bob Mannel's book (singular) "Mustang & Ford Small Block V8 1962-1969" has a plethora of details on this subject. For 1964 from pages 4-25 through 4-29. For the 1965 model year there is very little information (page 5-18) which most likely means that the design was of a carry-over nature. On the items I've looked for, it seems like he focuses on changes year over year, which makes sense - no need to be repetitive. I recommend you get a copy of the book, which is of course available on paper, but also electronically.