302 casting on a set of 318 heads

65Val said
360 heads are going to lower your 273 or 318 compression big time...they're open chambers.

that's y I need a set of CC 318 heads. Don't want 7 to 1 compression want 9 to 1 !
lower 273 block is all rebuilt with .030 pistons and mild cam. Just need Heads and away I Go !!!