Going through the old 455.. it was from a 68.. big valve “c” heads, 30 over rebuild in 2014 (been in storage since 2016) the deck to piston is .030.. and the pistons are 13cc dish.. with the .040” head gasket and 80cc “c”heads I believe my compression will be 9.5:1.. considering sending the heads to a friend of mine to get them milled to bring that comp closer to the mid 10s