TVS Swap -- what all is needed?

[Riddick]

False. Blower RPM is blower RPM, doesn't matter which pulley is changed the blower will spin at "x" RPM and make "x" boost if you go with a tiny upper only or a lower and a moderate upper. if the pulley ratio stays the same RPM stays the same, flow stays the same, power doesn't change.

+1. BMR Tech just laid down some serious torque with a 2.6 upper only on E-85. Main advantage with the lower is that you really dont have to worry about belt slip since you dont have to run such a small upper pulley.