Hello everyone, new here because I just sold my 02' lightning and bought a 2000 5.4 4X4 expy-really like it so far.
Anyway, I used to work for ATI procharger and for what RPM the 5.4 motors like, the roots/screw blower will be much more practical. Also, the Expedition kit uses (4) small idler pulleys which tend to burn up often. Other problems are the P-1SC model superchargers all leak. The procharger will give great "peak" power figures but low end torque will not change much. The eaton is without a doubt the more reliable, usable blower.