To be able to rev past your current Red line limits you will need some or all of the below done.

1) Valve train - Retainers, Springs, Stems
2) Head stud bolts
3) Aggressive camshafts Hi / Lo profiles.
4) CNC Machining of the ports - possible port & polish is also an option
5) Upgraded oil pump
6) Bottom end build - Balanced crank, oversized bore/pistons, forged rods, HD bearings, ARP Bolts
7) Programmable ECU.
8) Bigger injectors
9) Bigger TB and port matched IM to suit.
10) Decent exhaust & intake.

The above will definately allow you to increase your rev limits and will have the bottom end to cater for it - which in theory will increase your power/torque.

just depends if your down on spending the money / rebuilt.