Cams How do you choose one?

You choose a camshaft the same way you choose a carburetor. The same rule applies. You will be happier with a smaller one than one that's too big. You can take a totally stock engine, put a good hot timing curve on it and headers and make it scream. It's all relative. Too much of one thing will start the snowball effect that requires you to change everything else in the domino effect.