That's the big question is how much room in the lifters?

The head can stand -.100" easy. If he has a valve job done it will sink the valves a little too.

Realistically, you need to take .060" at least to do much good. I'd bet the lifters will be bottomed out or very near.

What did it have in it for a head gasket, steel shim? If so a Fel Pro will add about .025" back.