Well I think I know what he's trying to ask...

Engine A: makes 400hp N/A at 6k rpms

Engine B: makes 400hp FI at 6k rpms

What are the differences between the two?

Like Chuck said peak hp is peak hp. However, If you put both graphs on the dyno they may be different "under the curve". I would say that the N/A motor will have more linear numbers and the FI would be more peaky. Case in point... a 400hp v8 will have a different curve than a 400hp FI 4cyl.

-Mark