I could be wrong but seems to me OP goals are vague, is he looking for improvement on the track ? Does it need more top mid or bottom ? What parts of the powerband you spend most of the quarter mile time on and possibly focus on most to least etc..
Add I guess that miss answered your questions, just generally especially at higher hp per cid most additional mods to a fairly well built engine are only gonna improve part of the powerband and can subtract from others but not always.
