Hotrod,
You've obviously given this a lot of thought, but I need to point out that your idea for changing the spark advance is wrong. While you're correct in thinking you want less advance in a charged engine than a naturally aspirated engine, you will still want the spark to advance more as the RPMs go up. If you change the vacuum advance from port to manifold vacuum, you will actually have more advance at idle than you do at higher RPMs. This will cause a retarded spark at higher RPMs and overheating, definately something you don't want in a turbo motor. Also, I agree with 1-ton about not being able to use an intercooler with a draw-through, you need to keep the carb as close to the intake port as possible.
This is just my two cents worth so feel free to tell me to take a walk if you think I'm full of it
