Compression Ratio and Boost Query

I'm planning 9.0:1 and 15PSI on an LA, but that's with computer-controlled distributorless ignition and MPFI. Timing and charge cooling are imperative, especially on gasoline. You can do this on a properly set-up blow-through, but you'll need computer control over the timing to really maximize power. I highly recommend picking up Street Turbocharging by Mark Warner. Excellent book on the subject. I've read it a few times to drill the contents into my smooth brain.

Another excellent read is Designing and Tuning High Performance Fuel Injection Systems by Greg Banish. Much of the EFI stuff doesn't apply (some does), but he gets pretty deep into ignition mapping, which is critical to how much boost you can push through an engine. I've read through this one multiple times as well. It's a lot to digest in one pass.

Both are great books that I highly recommend. Unlike the interwebs, there isn't a bunch of incorrect, misleading, or conflicting information. I think it was Banish that said something about armchair experts having plenty of time to post because they're not out there actually doing it. Banish has done extensive OE fuel and spark mapping at both GM and Ford, so he's probably pretty well qualified.