The fundamental rule of an ICE applies:
Mass flow rate (m dot) will strongly effect max potential power (think restrictor plates).
Not sure on just how they corrected their numbers in terms of max airflow, listed at 330CFM. Corrected numbers usually factor in density and are given in mass/time (lb/min, kg/sec, etc) Another question is what is limiting the factor: blower RPM, bearing specs, or something abstract like the circular induction point (there the TB would connect to).