The basic principles are rock-solid; but granted, the costs would vary. Costworthiness is the issue
The basic essenstials are just sheer mechanical physics: get the engine to move more air, and move that larger air volume faster, and you achieve more power, end of argument (provided it is managed properly, mind you) THAT is what becomes the big issue, though--which is where standalnoe management comes in, a la Stinger, Tech II, etc. But again, that takes time, costs money, etc etc
I know it is not a bonehead job, takes time. But the basic principles of serious headwork, agressive cams, ramped-up electronics and management and etc are indisputable. Sheez--would love to have a good 10K to mess around with and actually have this done---see 400+hp in naturally aspirated--which I have no doubt can easily be had.