Feztalica-
There are so many different forced air applications to choose from... I think a desired hp goal should be decided first by the builder. Then create the best build formula for that desired HP, decide the internal upgrades then apply the proper AFI to that engine to reach your desired goal...
A 400rwhp motor can be built alot different then a 800rwhp motor...Besides when considering a build of that magnitude the internal motor building is a must and you have to also seriously consider drivetrain and tranny upgrades as well to handle the huge HP increases, both are equally important... Which I am sure all of you are already aware of..