Blower and Turbo motors need lower static compression. Somewhere in the 8.0 to 9:1 depending on how much boost you're going to run. As the boost increases, your cylinder will gain pressure and your final compression should be under 12.5 at maximum rpm to be safe on pump gas. Also, if running high boost you'll want to O-ring the block and the heads. You need to plan your build ahead of adding boost because the builds are a lot different than traditional aspirated motors, and more expensive too.
A good rule of thumb on a boosted motor is a good block with billet or splayed mains, a premium crank, billet rods, a good set of blower pistons and tool steel pins. You'll also need a cam grind that suits the application as both supercharged and turbo grinds are much different than traditional cams.
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