Ford Racing over-the-counter item:
This positive displacement “Roots” type supercharger provides instantaneous throttle response and tremendous mid-range torque.
6 psi boost pressure gives a 55-horsepower increase over production levels, and does not require aftercooling (4.6L SOHC only).
Unique one-piece supercharger housing/intake manifold design results in a very compact, rigid assembly.
Quiet, durable supercharger design with a lengthy, proven record in automotive application.
The space-efficient design allows the entire package to be installed with no hood or engine compartment sheet metal modifications. Production shock tower brace is retained.
All kit components are of highest original equipment quality levels, and thorough stepby- step installation instructions are included.
This kit is designed to be used with the production engine, requiring only the intake manifold to be changed. No internal modifications are necessary.
All required fuel system parts are supplied in hardware kit. Including high capacity fuel pump and 30 lb./hr. injectors.
Requires an engine management computer unique to this application which is included in hardware kit.
I think it's good for like 5hp 
