Before I would start changing your specific engine, I would put an accelerometer on the windshield, and measure/plot it's current power-curve.The Go-ProSS is a great tool, but there are much much cheaper methods.
I'm looking more for a daily driver type ride with decent power, should have 350hp that's more than enough for now and if I want more down the road big block, stroker, turbo or all :)
Whatever the power level I want to keep peak around 5000 rpm unless I change directions.