I only sent the head thicknesses as a guide for people to know what they were starting off with as the heads don't have any other markings.... as i said i would not go by this alone until i got more info...
If you had one of the high compression heads you have little to work with unless you want to go down the route of recessing the valves or removing material from the combustion chamber (which we had to do on a turbo engine I built over 30 years ago) and doing all that can be expensive and time consuming, and not something i would recommend that's why i was pleased to find the one i got just bought was a low compression version...as i had the measurements to work from !!
As time is money Ill have my machinist to work out the CC of the head when he does the valves as he has the equipment..the rest is as you said.