I'm not sure if anyone really answered this one yet about the blower, but one piece of info you need to remember is that the blower is not producing 10 lbs of boost statically. In fact, most only come to full pressure at full RPM. For example, my blower motor in the Daytona was actually drawing vacuum at idle, and all the way through 1100 when it started making boost. At 6500 RPMs, I had it set for 10 lbs even. So my "static" compression was only 7.25:1 with the pistons I was running.
If you were asking regarding total developed compression at RPM, I don't know how to figure that out. You would have to do the math for PSI over the area in question for total pressure.