The rev limited is programmed into the ECM for a reason and I would not change it even if I could. This is an older pushrod engine with a relatively heavy and complex reciprocating mass that will explode if over revved. Revving past reline the horsepower and torque fall off fast anyway. If you want see more rpms, get a double overhead cam rice burner. Or get an American muscle car that was built to take it. Horsepower is what counts. Maybe a turbo charged car is for you.