Cam duration is the rpm band.
As I see what you have now, you’ll find more power in air flow. Start with porting the head further. You didn’t say what you did for exhaust. A 1-3/4 header is what you can step up to for an edge in performance.
If you like the rpm range in which your car performs in and the gas mileage is OK, leave the cam alone. If you don’t mind stepping up in rpm range performance and maybe loose some mileage, increase the cam duration.
