They are advertised at 62 cc, but actually start out at least in the mid 60's. Shop said my heads needed some milling but didn't give specific original numbers. All heads will vary some due to production tolerences and the style of valves and valve job will make a little difference.
Need to watch the short installed spring height like Magnum heads unless you use longer valves, locks/retainers that give more installed height and/or mill the spring pocket.
Rocker geometry and contact needs to be checked. Some rockers may not line up quite right on the valve tip..
There are several older threads on these heads here and on other forums if you do some searching.