[cycleguy55]

Worth watching - Weiand Roots-type vs. Paxton centrifugal. Both used carburetors, and that created some issues with the Paxton blow-through. [ame]https://www.youtube.com/watch?v=EHg2uqJvLOk[/ame]

Summary:
Roots: More torque and HP at lower RPM, lower overall torque and HP
Centrifugal: Lower torque and HP at lower RPM, higher lower overall torque and much higher peak HP

Worth noting: belt slippage issues with both setups, though they seemed a bit of a bigger problem with the Roots-type blower.

Either way I'd go EFI, and FiTech has power-adder and blow-through configurations that would be worth looking at.