are they casting number "DOOE" ?? those are '69 windsor heads...pretty good heads , basically gt-40 irons.
you should hardended valve seats though...cuz they were designed for leaded gas, that and a good valve job, might as well port them while your at it and you'll have a really nice set of heads capable of running into the 10's w/ support
Take them too a machine shop and have them do the works on them, For about 1000 bucks those heads are great, my 83 ran a 10.06 on my 306 with those heads.