I found out I may have to compromise my goal for 1000 awhp. It may end up being more like 1000 brake horsepower (horsepower to the crank or flywheel). The only instrument to allow such incredible airflow is a large single turbo. The largest single turbo housings that will really fit with any sort of practicality are the honeywell garrett gt4094r (commonly knows as the gt40r) and the gt4202r (gt42r). The garrett dual ball bearing gt42r is good for right around 1000 brake horsepower. However, it seems that the gt4508r (gt45r) compressor wheel will actually fit inside of the gt42r compressor housing. This will allow a little more airflow from the single turbo to push past the 1000 bhp mark and start approaching 1000 all wheel horsepower. However, for realistic goals, its safe to say that I'm going to be shooting more toward the 1000 bhp goal.

Reference:

Garrett gt40r -> http://www.turbobygarrett.com/turbobygarrett/catelog/Turbochargers/GT40/...

Garrett gt42r -> http://www.turbobygarrett.com/turbobygarrett/catelog/Turbochargers/GT42/...