valve help

I don't understand why they need to be 10 over. If he is going to use over size valve heads, it would be better to use larger. If he is talking about over size stems (because the guides are worn) it would be better to replace the guides. Better check with him and get it clarified. A common over size valve for the slant is 1.70 and 1.44

1.72 and 1.46 are 100 over, not 10 over