Here is the Ford data for cylinder heads that I have - it might be a bit more accurate in some cases but don't take it as gospel because there is a lot of info from Ford that is full of holes.
Lets also remember that fords ability to cast the heads accurately greatly depended on the day of the week. The chamber sizes on factory ford windsor heads of the 60s' and 70s' were seldom accurate from one chamber to the next on individual heads. I have personally seen heads with variations of up to 7ccs' from one chamber to the next on individual heads...
WOW! that is a lot! My 75 351W heads were all within 1.5 CCs and I was able to equalize them at 61CCs.