Techinspector is right. Your heads are probably 1.94/1.50 valves. even though they are camel hump heads and some of the best of their day, there were much better heads made to fit your application with a lot less trouble and rigging. Someone somewhere would like to have the heads you have for a restoration project. Not much good for what you want to do. Good luck with your project and don't get discouraged. It takes a while to get everything down.
Ed