all thats really necessary to safely raise the redline is valvetrain (cams, springs, retainers, and depending on goals, valves), The flow of the head wont affect redline, but it will determine how much power youre making @ redline (and everywhere else in the powerband).

But be sure to keep bottom end in mind. Think of it like this: cams don't make more torque, they just shift the torque curve upward, so the bulk of the power is being made higher in the powerband. And the higher in the powerband, the more hp they will make (since hp is just a function of torque and rpm [ hp=tq x rpm/5252])... At the same time, they can drastically reduce low end torque... With a typical stage 3 cam (like toda spec C, for instance) you'll be making tons of hp, but there will be nothing below 4500 rpm, making it difficult to drive around town, and causing an erratic, lumpy idle. Cam profiles like this are great for racing, but can be a pain in the ass for daily driving. For my transportation/daily driver, I wouldn't want to go past a stage 2 cam, but if you want that screaming 10k redline, its up to you. (you would need to consider revising the shortblock beyond pistons at that point).