Increase Head CC's

I want to raise my head cc's from 60 to 68 to use available pistons. I'm trying to avoid a 13cc dish in favor of a 5.5cc flat top to get the compression around 11.3-11.5. The dish is 1.450 compression height, the flat top is 1.465 compression height and matches my current 23.5cc dish piston. I don't want to deck the block. Opinions, feedback?