Another "what will it make", but a little different

FelPro 8553 head gasket.......12cc
typical valve notch volume......6cc
587 head nominal volume.......72cc
total TDC volume of..............90cc

90cc TDC volume in a 416 will yield 10.4-10.5
if you can open the heads to 75cc you'll have 10.1
sink the valves a bit, along with deshrouding cuts, and blend the chamber to the valve job/deshrouding work will probably increase the volume by 3-4cc