Classic/Antique Car Repair: 1947 Packard head, combustion chambers, combustion chamber

Question
First, Thanks for your help.  I have a '47 Packard 245 6 cylinder apart for overhaul.  How much can I mill the head before I have valve problems?  The cumbustion chambers measure 96cc so I think the head has not been milled before.  The cam lift is stock.  Thanks again.

Answer
We used to figure that .030" was about the limit back in the day. However if you are concerned that it might have been milled before and the tolerances are getting thin between the valves and the roof of the combustion chamber try the old playdough trick. Line the roof of the combustion chambers in the head with about a 1/4 to 1/2 inch thickness of playdough. Then bolt the head on with an old gasket. Turn the engine over two turns, that will open and close all the valves. Then remove the head and the impressions of the valves will be in the playdough and you cam measure the thickness. It will tell you if you have room to mill more off the head. That is the way we did it in the day.
Brad