Max compression for pump gas iron head

Cheif, most of the info about what I am considering is in the posts. The current stock motor info is really not relevant since I am building a new one. Anyway, I am considering 59cc 302 heads, .030 bore, comp 268H cam (.454/218@50), assume a .039 gasket as Rumble referenced.
The stock pistons in the stock block sit .071 in the hole. Stock 318 pistions I understand have a 1.720 compression height. The 84 to 90 ones have 1.745 (.025 taller), KB167s look like 1.81 which is .090 taller. If I square deck the block and it takes .020 to do that I only have .051 to deal with before 0 and if I use the 1.745 pistons I am .026 in the hole. That looks like 10.28 to 1.. If as BJR says I have to go more off the block it obviously jumps from there.
I don't see how the Keith Blacks would really work.
Did I do this calculation right?