Thanks for that. I’m going to do it.
The pistons are recommended for closed chamber heads. Hughes sells a 408 package for magnums with these pistons. They advise a thicker gasket if necessary but don’t give limits on how much protrusion is ok.
They were chosen for the - 25 cc factor to get the compression into the upper 9s with 61 cc heads.
Makes me think I have short decks. To my knowledge only a .010” cleanup was done but I have to ask if they took more for some reason.
I suspect if the pistons are milled and standard gasket used my compression will be too high.