273 Supercharging?

I know you are talking a centrifugal but you may want to look at a B+M roots style. Member jimjimjimmy has a complete setup for sale for a good price I believe. I picked it up for him and it appeared to be in very good shape. You would still be able to use you EFI and the wow factor is there as well. Just a thought.

Other than that I would say to keep your compression down and don't skimp on the cam. A cam for boost is a lot different than one for N/A engines.

Let the exhaust breath as well, that is where most bottlenecks occur in boosted engines. Go hang out in the Boosted forum and also visit YellowBullets boosted forum, it is a good one.

Jack